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THE UNIVERSITY OF KANSAS 

SCIENCE BULLETIN 

Vol. XXXVI, Ft. I] June 1, 1954 [No, 6 



A Revision of the Bee Genus CoUetes in America North of 

Mexico ( Hymenoptera, Colletidae) * 

W* P» Stephen t 

Abstract: This paper consists of a monogmphic revision of the bee genus 
CoUetes in America north of Mexico. It is primarily a taxonomic study although 
some information is included on the biologies of several species, some specula- 
tion on the phylogeny and distribution of tlie genus, and a brief consideration 
of the nomenclature of the male genital segments. 

Previous to this paper some 167 fonns had been described from America. 
An alteration of previous synonymies and revision of existing forms have re- 
sulted in tbe treatment of 95 species and 16 subspecies which are described in 

detail. 

Twelve new species arc described: CoUetes (iridus, C. arizonenms, C. bea- 
merontm, C. hulbotibialis, C. cUiatoides, C. kansensis, C. longifacies, C, mich- 
eneri, C. mitcheUi, C, saritenms, C. swenki, and C, timherlakei. In addition, 
two new subspecies are named: CoUetes fulgidus langiplumoms and C. puncti- 

pennis maums. 

CONTENTS 

PAGK 

Introduction - - ■ - - 150 

Notes on Morphology of the Male Genitalia 153 

Bionomics . , , ■ — ^ 155 

Distribution and Phylogeny 164 

Geographical Variation - . . . , ,....,,.. 169 

Measurements - - . . . , . . , 169 

Description of the Genus . . , , 170 

Key to the Males , . , , ,,..... 173 

Key to the Females . .,,...... 188 

Descriptions of the Species ,.,,,... 201 

il O U en Lia , ^ * • , • ^ ■ - ..ii,*^^^^, + ►*,,<, »..-itii|. M V -L 

Acknowledgments . , . , ^ ^ 502 

References Cited ..__....., 503 

Index to Species and Subspecies ,,,..,..,,, 507 

Fio"iirf><; oil 

Maps , , . . 524 

* Joint contribution from the Department of Entomology^ University of Kansas ( Contri- 
bution number 848) and from the Division of Entomology, Science Service, Department 
Agriculture, Ottawa, Canada { Contribution nombcr 3097}, 

t Present address: Oregon State College, Corvallis, Oregon, 

(149) 



150 The University Soence Bulletin 

INTRODUCTION 

The bee genus CoUetes abounds in America north of the Tropic 
of Cancer and is widely distributed throughout the world, with the 
exception of Australia. This study is limited to those species oc- 
curring in America north of Mexico, for material from Mexico and 
the Central American countries is meagre and the areas of collection 
remote. 

The work is primarily of a systematic nature and contributes little 
to an evolutionary or phylogenetic study of the genus- However^ 
in conjunction with Noskiewicz's (1936) treatise on the Palearctic 
members of the genus plus a critical treatment of the Latin American 
fauna, it should form a suitable basis for the inauguration of such 
a project. 

Swenk (1908) published the first extensive systematic paper on 
the American species of the genus. His work considered twenty-six 
species possessing some black thoracic pile in either or both sexes. 
He experienced a great deal of difficulty in obtaining accurately 
determined material, and recent inquiry indicates that he had oppor- 
tunity to examine but a few of the types. Despite his effort to avoid 
the use of chromatic characters for species diflerentiation, he was 
occasionally forced to do so; where these lapses occurred the spe- 
cies picture was obscure. In spite of these shortcomings the Swenk 
work was laudable and unique until the Timber lake papers on Colo- 
rado (1943) and California (1951) CoUetes appeared- In addition 
to these treatises, several species lists and incomplete keys have 
been compiled, usually accompanied by descriptions of new species. 
All, except the Swenk work, are regional in scope and are unsatis- 
factory to workers outside of the zones covered. The original de- 
script! on s are, for the most part, unsatisfactory in the light of present 
knowledge J frequently referring solely to the color of the body pile 
and to other characteristics now known to be of infraspecific value 

onlv. 

As a result, all species are herein redescribed with the exception 
of a few not available to me and a few known only from single fe- 
males. These are listed in the text and addenda with tlieir original 
descriptions. Most, if not all, of the monotypes may eventually 
prove to be conspecific with better-known species, but further in- 
vestigation is necessary. An attempt was made to standardize de- 
scriptive techniques: holotypes, paratypes, or topotypes, in descend- 
ing order of availability, were selected for the basic description with 
variation over tlie species range recorded in a preamble or postscript 



Revision of the Bee Genus Colletes 151 

to each description; the first paragraph of the description deals with 
the distribution, density, and color of the pile of the body, beginning 
at the clypeus and extending progressively caudad, terminating with 
an account of the pubescence on the metasomal sterna; the second 
paragraph inckides a discussion of the integumental morphology of 
the insect in the same sequence. In most of the descriptions of spe- 
cies a brief summary of the characters of the seventh ventral plates 
and capsule of the male is given, and in each of them there is refer- 
ence to illustrations at the end of the work. 

The locations of the types of the new species are indicated in the 
text, and insofar as is x^ossible the paratypes may be found in the 
University of Kansas collection, the Canadian National Collection, 
the United States National Museum, and my personal collection. 

The conventional synonymy precedes the descriptive portion of 
each species. Included are some records, obviously erroneous^ 
that are well out of the known range of distribution for the species. 
In some instances I have had an opportunity to examine material 
(of Swenk, Graenicher, Griddle, etc*) upon which earlier publica- 
tions were based. In an effort to make the work as comprehensive 
as possible the reference lists have been included in their entirety. 
Where any question exists in my mind on the validity of a specific 
record, a clarifying note, in parentheses, follows that item. Refer- 
ences to the Cresson (1887), Dalla Torre (1896), and Michener 
{In Muesebeck et aL, 1951) catalogues have not been included for 
it is felt that their inclusion would entail unnecessary repetition. 

The greatest difficulty in tlie descriptive phase of this work was 
experienced with the color of the body pile. This problem Kes not 
only in the fact, as Swenk suggests, that "the original color under- 
goes a rapid fading, so that a specimen in which the hair of the 
thorax and face was of a bright yellowish color when fresh will, in 
a short while, fade to pale grey without a tinge of yellow . . !' 
but also to an equal or greater extent on the inherent polychromatic 
nature of the pile. In a number of species there is so much color 
variation that accurate description would necessitate the consider- 
ation and subsequent treatment of at least twenty-five per cent of 
the individuals. C, thoracictis is the prime example of this variabil- 
ity. Typically this spfecies has the pile of the body, particularly 
of the head and the thorax, uniformly ochreus to ferrugineous, but 
in many specimens the pile is tawny or dusky grey much as in the 
closely related species inacqualis Say. Other individuals of this 
species have a few hairs of the mesoscutum and scutellum so deeply 



152 The University Science Bulletin 

dusky-ferrugineous that they may be confused with black. I 
suspect that some of this variation can be attributed to fading but 
this is not the only cause of it. Throughout the genus there are many 
species in wliich a little black pile is present on the scutellum or 
vertex or both of a large percentage of the population but is absent 
in other individuals. Similarly, variation in the intensity of yellow 
pigmentation of the j>ile often occurs on specimens taken in a single 
area during a single flight season. 

There is little doubt that the presence of abundant black hairs, 
whether on the face, vertex, or thoracic dorsum, serves as a char- 
acter of value. However, I doubt whether it is of much phyletic 
significance. The presence of black pile in some species in many 
diverse groups merely indicates that the character has arisen inde- 
pendently and repeatedly during the evolution of the genus. 

Hazardous, as a specific character, is tlie use of slight differences 
in the density of body pubescence. With age riiany, if not all, 
species lose pile, probably because of abrasion during the construc- 
tion of their nests. The thoracic and metasomal terga are most sus- 
ceptible to repeated contact and, consequently, the metasomal 
fasciae are often reduced or absent, depending on the age and sex 
of the specimen. Despite its limitations, I do not advocate that 
consideration of the body pile be eliminated in species determina- 
tion, but caution against its use and when possible would restrict it 
to the secondary role of characters to be employed principally in 
substantiation of conclusions based on other morphological char- 
acters. 

A number of characters regularly used previously in species 
recognition have also proved unreliable when generally applied. 
Those dealing with die intensity of color of some morphological 
structure are of little value, except w4ien applied to species of a 
restricted range. The degree of melanism varies in the general 
body color of the insect; in the coloration of the underside of the 
flagellum; in the extent of red and black on the apices of the man- 
dibles; in the color of the nervures of the wing; and in the shade of 
the tarsi and tegulae. These have all proved equally unsatisfactory 
for the more widely distributed species, and reference to such char- 
acters has been kept to a minimum. 

Difficulty in species recognition is by no means restricted to 
chromatic variation. In the widely distributed species minor vari- 
ations are found in the punctation of the clypeus and vertex, the 
sculpture of the basal area and posterior face of the propodeum^ the 



Revision of the Bee Genus Coli.etes 153 

X^atterning and pitting of the metanotum, and the pectination of the 
spurs of the hind tibiae to the extent of negating or impairing the 
use of the structures as specific characters. Again, it must be empha- 
sized that the above characters become increasingly useful in species 
of restricted distribution, vt^here geographical variation becomes a 
negligible factor. 

NOTES ON MORPHOLOGY OF THE MALE GENITALIA 

The variation in terminology of the various structures of the pri- 
mary copulatory organs of the male is disturbing; the list of terms 
is resplendent with synonyms and appears to be increasing with each 
of the more recent papers. Crosskey (1951) has done little to 
clarify the situation with his introductory statement^ "It has been 
conclusively shown that the male genitalia of Hymenoptera are 
entirely phallic in origin." Few morphological problems in ento- 
mology remain so unsettled. His failure to consider the basic con- 
tributions by Crampton (1919, 1920, 1938), Singh-Pruthi (1925, 
1929), and Michener (1944) leads one to consider the statement 
no more than a personal expression of satisfaction with the conclu- 
sions of Snodgrass (1941), Despite the uncertainty that enshrouds 
the homologies of the primary copulatory organs I find the work of 
Michener and Crampton much more plausible than claims for 
exclusive phallic origin of tlie capsular structures. Michener ( 1944) 
wrote; *'Holometabolous insect larvae do not have legs' on the ninth 
abdominal segment, which is the segment upon which the claspers 
are situated, or if appendages are present as in the larvae of Tri- 
choptera, they give rise to claspers. It seems certain then, that at 
least the outer claspers, and the inner ones as well except possibly 
in Orthoptera, are, like the gonopore, associated with the ninth 
abdominal segment/' The appendages which do eventually appear 
on the ninth segment in Hymenoptera are presumed to be serially 
homologous to the "legs/' As Michener points out, the copulatory 
organs are much less likely to be new structures of phallic origin 
than derivatives of pre-existing structures. 

The terminology used in this paper to describe the primary copu- 
latory organs (capsule) is that of Michener with slight modification. 
Frequent reference is made to the membranous expansions, or wings, 
of the penis valves for they offer excellent specific and group char- 
acters- The ventral wing is broad and readily distinguishable in all 
sj3ecies except C. ciliahis Patton, in which it is reduced to a semi- 
lunar preapical expansion, A number of species, particularly those 



154 



The Uni\^rsity Science Bulletin 



of the consors group, also have the dorsal margin of the penis valves 
broadly convoluted and extended laterally in a plane parallel to the 
ventral v^ngs* These two expansions I have termed the dorsal and 
ventral wings of the penis valves. This is done despite Timber lake's 
previous use of the term "lateral wing" for the ventral lamina. As 
both wings often occur as lateral projections I feel that the use ol 
^'lateral wing'' would eventually add to tlie confusion. I have fol- 
lowed Snod grass' terminology for the apical portions of the volsellae, 
i. e., ctispis for lateral process, digitus for median process (Figure 
87), 

Noskiewicz (1936) based his capsular nomenclature on the work 
of Strohl (1908) and frequently referred to appendicuhir terms as 
employed by Schmiedeknecht (1882-1884). An attempt to syn- 
onymize the various names used by the principal workers in dealing 
with the copulatory structures of Hymenoptera is shown in Table L 

I have treated the seventh metasomal sternum as being com- 
posed of two septirate plates attached to a narrow transverse basal 
apodeme. Throughout the genus the two plates are united at their 
niediobasal margins. The seventh ventral plates, despite their 
simplicity, are undoubtedly the most useful morphological structures 
for species differentiation, and I have arbitrarily applied names to 

TABLE I 

Synonymy of tenns applied to the primary" copulatory organ in Hymenoptera 



Mjchener (modified) 


Snodgrass 


S chm i ed ek necli t 


Stroll I 


Timberlalce 


gonobase 


basal ring 


cardo 


cardo 




gonocoxite 


parameral plate 


stipes 


fvalvae 


stipes 


gonostylus 


parameres 


laciuia 


lexternal 


apical segments 
of stipes 


penis valves 


sagittae 


sagittae 


sagittae 


sagittal rods 


dorsal wing 
ventral wing 






'liiincllae 
t 


dorsal wing 
lateral wing 


volsellae 


volsellae 




valvae internal 


volsellae 


cuspis 


cuspis 








digitus 


digitus 









portions of the plates for ease in verbal description. The rounded 
basal points of attachment I have termed the "basal articulatory 
condyles" because of their condylar shape and their presumed 
function in articulating the x>lates with the body. The apical por- 
tions of the plates are broadened and possess dorsal pubescent cov- 



Revision of the Bee Genus Colletes 153 

erings of variable density and distribution. The length, density, 
and distribution of the hair patterns offer excellent differentiating 
characters. Attempts were made to illustrate all plates with ac- 
curacy; in a few species the hair pattern may be slightly overempha- 
sized to aid in their recognition. These broadened apical portions 
of the plates are referred to as "discs/' Occasionally reference is 
made to a usually petiolate sector between the disc and condyle, 
termed the "neck*' (fig, 86). 

Noteworthy is the unique nature of the seventh ventral plates of 
C, thoracicus Smith, a sibling species of inaequalis, that is found 
along the eastern and southern seaboard of the United States. There 
are a few minor external features by which these species can be 
separated, but occasionally genitalic examination is necessary. The 
most interesting feature of thoraciciis is the fact that it shows strik- 
ing intraspecific variation in the form of the seventh ventral plates. 
The plates may be weakly trilobate with the lateral lobes free along 
the median margins, partially fused to the median lobes, or united 
completely to form a bilobate apex. This is the only species in which 
exceptions in these characters have been observed within popula- 
tions, although subspecific differences occur rather frequently. The 
material examined shows that the variation occurs at random 
througliout the range, to such an extent that it is impossible to tell 
which of the three forms predominates. 

BIONOMICS 

The species of Colletes are solitary, tending to be semigregarious 
in selection of their nesting sites, exhibiting, as far as is known from 
the few kinds studied, species preference for certain soil types and 
textures. 

The conditions believed most primitive are those common to the 
various groups of species known in America today. The gregarious 
tendency; the simple, straight nesting tube probably not extending 
more than a foot below ground level and having the cells in a row; 
the well-mixed pollen and nectar supplies in each cell; and the com- 
plete lining of the nest tunnel with salivary excretions appear to 
constitute the more basic ancestral characteristics. Unfortunately 
biological data are so sketchy that one must be overimaginative to 
attempt even so much as group phylogeny with the material at hand, 

C, inaeqnaUs Say is the only American colletid on which a credit- 
able amount of information has been accumulated, and from these 



156 The University Science Bulletin 

data we can assume the species to have undergone considerable 
evolution from its progenitors. 

Several contributions have been made to the biological knowledge 
of this species of Colletes^ of which the most outstanding is the 
work by J, B. Smith (1900, 1901 )• (The original determination of 
the species as C. compact a by W, J. Fox was in error ^ as was sub- 
stantiated by Swenk's re-examination of the Smith material.) In- 
teresting but incomplete information on C. compactus Cress on by 
Phil and Nellie Rau (1916), and on C. nifithorax {= thoracictis 
Smith) by Parker and Boving (1924), has shed some light on the 
biology of these two species but much more observation is necessary 
before either can be considered to be complete- 
Two papers by Friese (1912, 1922) contain summaries of part 
of the biological knowledge of the Palearctic CoUetes fauna. Both 
works deal with C. daviesanus Smith, a widespread species of north- 
ern and north central Europe and Asia. Malyshev (1923, 1927) 
and Miiller (In Noskiewicz, 1936) contributed abundantly to the 
life history of C ciinictilarius L,, a very close relative of the Nearc- 
tic C. inaequalis. It is not at all remarkable to find the biologies of 
these two species almost identical. 

An excellent treatise on the biologies of several species of South 
American CoUetes is given by Claude-Joseph (1926), and extracts 
of that paper are presented below* 

Some additional data on C, inaequalis, obtained by me during the 
sirring of 1951 in Douglas County, Kansas, sux^plement the Smith 
paper on the life history of this species. I remain indebted to Dr. 
Smith for a great deal of that which follows and, to maintain coher- 
ence, have omitted the quotation marks where his information was 
used. 

The species was first noted in abundance on the 20th of April in 
Kansas, a full month later than those observed by Smith. Groups 
of 15 to 30 mounds of sand and silt were found by chance along the 
margin of a wheat field in the lowlands along the Kaw River. From 
the color of the exposed sand and a knowledge of the soil strata, it 
was calculated some burrows w^ere at least 18 inches deep and that 
others were in the process of excavation. During the two weeks 
following the first observation, little mounds appeared in abundance 
all along the sheltered margin of the field, with few extending into 
the open adjacent wheat field. Males were noted in great numbers 
at the time of the first visit, hovering constantly over and about the 
excavations J but for some obscure reason they would become less 



Revision of the Bee Genus Colletes 157 

and less obvious towards noon. Very few males were noted in the 
afternoon but the next morning they reappeared in droves and re- 
peated the violent buzzing about the nests. The earlier the hour, the 
closer they flew to the ground. It was assumed that the males were 
awaiting the appearance of emerging females, but during the days 
which followed no actual coition was observed. During these first 
few days the females did not leave the nests but would frequently 
come to the opening and bask in the sun. Occasionally the female 
would descend and in a few minutes the abdomen would become 
visible and the hind and middle pairs of legs would violently fling 
the sand from the entrance. The reaction of the occupants was 
noted on several occasions where the mouth of the nest had been 
damaged; and in each instance after the tunnel had been cleared 
the bee would move up and down, with its mouthparts and fore 
legs working vigorously close to tlie tunnel wall as if it were in the 
process of aj^plying a very thin adhesive. The species is known not 
to line the tunnel with visible quantities of material, but it may se- 
crete a very fine film to strengthen the walls leading to the celL 
Partial verification was obtained on the excavation of a number of 
nests in which the sandy-silt tunnel walls adhered more closely than 
the surrounding medium; often pieces of the tunnel could be re- 
moved intact. 

On the second day of observation the females began gathering 
pollen and presumably nectar, each trip falling into a similar pat- 
tern. The female would project the head and then the thorax slowly, 
as if in fear of a foe. If a shadow fell across the mouth of the tunnel 
or the observer moved, the bee hurriedly clambered down the hole 
and used the head as a plug. Finally, when left undisturbed the 
bee would emerge^ circle the entrance once or twice, and leave for 
the food source. The return to the nest was usually direct, but on 
a number of occasions the female would become lost, in which case 
she would circle the area, often settling and walking over the soil 
to enter first one, then another burrow. This process was repeated, 
at times requiring up to 20 minutes, before she found her own nest. 
There was considerable variation in the time required for a female 
to secure a load, depending presumably upon the supply of pollen 
and nectar as well as the distance to the source. One female re- 
quired 13 minutes to return laden and another took 47, the mean 
time per trip approximating half an hour. The deposition of the 
collected food required much less time, some emerging 4 minutes 
after entering the tube. Again, however, there were great diflFer- 



158 The University Soence Bulletin 

ences in the time required to emerge. One bee remained in the 
burrow for 1 hour 5 minutes before reappearing; it was assumed 
that the female was in the process of seaHng a cell and preparing 
another. 

By the 3rd of May many of the burrows were filled in and the 
flight activity of both sexes had become reduced- Contrary to 
Smith's observations there was no preponderance of males following 
the cessation of female activity- 
Later, burrows in use were traced, each yielding meagre finds. 
The first and second tunnels ended barely 12 inches below the sur- 
face in partially completed cells and despite continued digging 
yielded nothing. A third excavation was made on filled-in observa- 
tion burrows, known to contain good supplies of pollen. The first 
22 inches of the tunnel were followed without too much difficulty 
until the first (actually the last formed) cell was reached. The 
female had apparently filled the tunnel with light-colored sand sur- 
rounding the burrow entrance and the solidly packed yellow sand 
stood out well in the darker sandy silt. There is evidently no com- 
mon form to the burrow, for the first 12 inches curved weakly from 
a vertical orifice and the last 10 inches ran almost parallel to the soil 
surface- Another curved sharply 3 inches below the surface, ran 
sub-horizontally for a few inches, and then dropped almost verti- 
cally another 18 inches before the first cell was found. Still others 
curved weakly throughout their length. Below this first cell the 
path of the tunnel was nowhere evident and excavation was con- 
tinned by carefully removing layers of soil from an area two feet in 
diameter. As many as five cells were uncovered from a single 
burrow, each lying on separate horizons below the last-formed cell^ 
and in no instances were these cells in line. The deepest cell was 
34 inches below ground level; cells from the nests examined were 
separated by as much as 12 inches in a horizontal plane and 5 inches 
vertically. Smith's statements seem most logical to account for this 
pattern in inaequalis. The bee digs down from the first to the ex- 
treme depth of the burrow, then runs off to one side for t\vo to four 
or rarely six inches, makes and fills a cell, and lays an egg in it. 
Two or three inches higher another lateral is started, running in 'a 
different direction, and the sand taken from this lateral is dropped 
into the main tube^ from there it washes into the first lateral so that 
when the second is completed the first is well filled. The second 
lateral is filled with material from the third if a third is run and, 
finally, the entire tube is filled. 



Revision of the Bee Genus Colletes 159 

Five of the eleven cells unearthed v^ere undamaged and were 
taken to the laboratory; three had been torn open in the process of 
removal, two were infested with ants^ and one had desiccated. The 
cell is approximately 15 mm, in length and 5 mm, in diameter, with 
the distal end rounded and the proximal end abruptly truncate, at 
times weakly concave. In texture the capsule, made presumably 
of salivary secretion, was thin and transparent, tending to show 
little pliabiHty and tearing easily. It may serve to protect against 
soil organisms, dirt, and desiccation. 

Claude-Joseph states that tlie viscous substance making up the 
membrane is secreted by glands at the base of the tongue, under the 
clypeus. It then descends by vessels to the terminal lobes and 
opens into the ciliated zone, which spreads it in a fine film. 

The food stored in the brood cells is a pasty mixture of nectar 
and pollen, probably derived from a number of sources visited by 
tlie female, e. g., Cercis canadensis, Salix, Priinus. The cell is half- 
filled with food, and the egg, which is large^ is attached to one side 
of the cell by one end and so curved that the opposite tip rests on 
the surface of the food mass. The egg is slightly more than 3 mm, 
in length. After the egg is laid, the upper end of the cell is closed 
by means of a flat disc, which is set in a little from the ragged upper 
edge. Smith calculates that the interval from the beginning of tlie 
burrow until the first egg is laid is from 18 to 20 days. 

Two cells were found in which the larvae had just hatched; at- 
tempts to rear these to maturity failed. The young larvae retained 
a position very similar to that of the egg for a long time, with the 
mouthparts resting on the surface of tlie soupy food mass* Many 
of the cells taken up a month after the active flight dates were 
undoubtedly from the earliest burrows; hence the egg stage is an 
imusually long one. 

On July 1 Smith unearthed four cells in which the larvae were so 
far developed that they came near to filling tlie cell The bulk 
of the food store had been devoured and growth must have been 
nearly completed. Unfortunately further samples could not be 
obtained later in the season, and the date of pupation is thus left 
undetermined. It is uncertain whether the insects reach the adult 
stage in the fall and winter in the ground, or whether they winter 
as mature larvae and change to pupae and adults very early in 
spring. 

Malyshev (1927)5 working with C. cunicularius, reports the fol- 
lowing observations on that species: ". . . At the end of July, 



160 The University Science Bulletin 

July 27, 1917, in the vicinity of Kursk, I found a single cell occupied 
by Colletes which contained an unpigmented pupa. Three other 
cells v/ere found in Borisowka on July 2, 1917, containing white 
pupae with pigmented eyes. 

"The first young bee was noted in a nest in mid August which T 
had kept under observation since April. By digging the thawed 
out earth ( March 29, 1916 in Borisowka ) I found a matured male. 
Excavations on April 6, 1917 yielded two cells with females prepared 
for flight, four cells with mature, living larvae and more earth filled 
cells from previous years. Thus the development of the larvae was 
observed. On the 8th of July, 1917 the larva transformed into a 
pupa and on the 22nd of July, that is two weeks later, it had wings 
and had transformed into the adult female. The latter overwinters 
without leaving the cell, C. cunicularius overwinters either in a 
mature stage (which appears to be customary) or in a stadium of 
the resting larva ( diapause ) . . , ." 

In view of the close relationship that exists between cunicularius 
and inaequalis, it would not be remarkable to find inaequalls exhib- 
iting similar variation in its overwintering form. 

Observations on C. succinctus L. by Mayet ( 1875 ) indicate that 
the males are first to emerge, and search for the females much as 
those of inaequalis. Once fertilized, the females begin to construct 
their nests, employing a used burrow or starting at a new site. The 
sand is loosened with the mandibles and is ejected from the burrow 
by means of the legs and by curving the abdomen under the body. 
A gallery may be constructed in a single day when new nests are 
being formed or in several hours when the bee utilizes an old burrow. 
The cell is formed as in inaequalis and requires eight to ten trips to 
fill. The bee disgorges the nectar with some force, and a specimen 
placed in a glass tube dispelled the nectar in a small stream to the 
end of the tube. After the egg is laid, the cell is closed and covered 
with several layers of material similar to that which forms the rest 
of the cell. The larva of this species begins feeding in the fall and 
continues to develop the following spring. Pupation occurs about 
the middle of August. The adult bee emerges fifteen days after 
pupation and remains within the cell for about six days. It then 
breaks its way into the gallery, where it remains for ten to twelve 
days before emerging to mate. 

C. daviesanus, differing greatly from the above, was found by 
Friese (1912) to tunnel "in vertical sand stone and clay walls. The 
circular path runs diagonally down in the layer of sand and curls 



Revision^ of the Bee Genus Colletes 161 

to one side at the end, reaching ahnost 10 cm. into the wall. The 
inner wall of this round burrow is painted with a hardened liquid 
which upon examination proved to be a very fine spun lining which 
covers the inner wall of the nest and is then painted with saliva* In 
this setting the bee deposits the gathered pollen and seals off a single 
cell with a hyaline lid, which forms the arched base of the following 
cell; in this way the individual cells form a tube, with one segment 
projecting into the other, . . . One finds as many as 10 such 
cells joined in a brood chamber but more often less; other authors 
have reported 20 cells per brood chamber. . . . The nests, 
which were formed during tlie previous July and August, have half- 
grown larvae by the spring of the next year (March 28), With the 
advent of warmer weatlier, the larvae begin to eat the remaining 
pollen, working from the center to the outside of the cell, and reach 
their full growth by the middle of May. I observed the first pupae, 
with only the eyes pigmented on June 11th , . . and by the 
beginning of July the pupae were further pigmented and hardened 
so that I expected free flying stages by middle July; however it was 
July 27th before there were abundant numbers in flight/' 

Michener (in litt.) reports that at Montara, California, C. fulgidus 
longiphnnostis Stephen nests in great numbers in banks and that the 
cells are constructed end to end in the burrows as in C. daviesantis. 

A few nests were unearthed in the vicinity of Ottawa, Canada, 
during the summer of 1950 and had the tunnel lined with a 
material of cellophanelike texture. The species is believed to be 
C. kincaidii CockerelL 

Claude-Josei>li's (1926) thorough report on the Chilean species 
of CoUcfes exemplifies the diverse habits of the genus in that locale. 
The galleries generally are cylindrical, winding, often branched, 
and usually deep, with branching or winding characteristic for each 
species. The cells occupy the ends of the galleries or tlieir branches 
and may be isolated or deposited in linear series* Linear series of 
4 to 8 cells are not uncommon in araucariae Friese, cyanescens Hal., 
and hicolor Smith, whereas others have pectinate or bifurcate nest- 
ing tubes with single cells terminating each short branch. One of 
the most interesting sites is that of C ciliatus Friese, which is found 
in the vacated cement abodes of Odynetus htiTneralis or in the dry 
branches of Penmus and Kageneckia spp. The cellular membrane is 
semi transparent and gUstening and varies in turgidity witli each 
species. Each cell is constructed completely, except for its cover, 
before provisioning is begun • Apparently both nectar and pollen 

6—1542 



162 The Univebsity Science Bulletin 

are collected in a single trip, for when tlie bee returns to the cell 
the insect turns around so that the abdomen faces the bottom of 
the cell, and combs the pollen from the posterior femora. It then 
turns its head about and disgorges tlie nectar, mbdng it little by 
little to obtain a sweet paste. When the bee has gathered the 
quantity desired it excavates the surface of the paste and deposits 
its egg. The larva of C. armicariae was observed to move feebly 
over the surface of the paste, eating slowly into its food, and dis- 
appearing within two or three weeks. 

Once die egg has been laid the bee begins to form the closing 
meiubrane to the capsule. The tongue is touched against the cellu- 
lar margin and a droplet of a viscous substance is deposited; the bee 
then lowers its head vertically and pulls up a fine thread across the 
opening. With continuous to and fro movements across the en- 
trance, it forms a series of threads which transverse it in all ways. 
The tongue again passes over the threads thus formed, but this 
time the viscous material oozes from its lobes into the pores of the 
web, forming a thin membrane over the top of the cell. 

The egg hatches within a couple of weeks, depending upon the 
amount of heat absorbed by the soil. After maturity the larva re- 
mains immobile for several weeks, during which digestion and as- 
similation proceed slowly. Then a period of reactivation sets in and 
a yellowish fluid flows from its mouth. This substance is spread by 
the buccal organs all about it and against the cell walls to form a 
secondary envelope, in which it pupates. The apparent inactivity 
lasts for the duration of metamorphosis. 

Unlike inaequalis, the Chilean species never close the galleries 
that lead to their nests, and at the most gather a few grains of sand 
in front of the last-formed cell. This condition leaves an open door 
to a number of hymenopterous and dipterous parasites. 

Noskiewicz is obviously in error in stating that all CoUetes have 
but one generation per year, for among the American species many 
have a spring and a fall generation, e. g., texanus Cresson, ivickhami 
Timberlake, hirkmanni Swenk, louisae Cockerell, daleae Cockerell. 
The presence of spring emergents {inaequalis Say, etc.), summer 
emergents {kincaidii Ckll, etc.), and fall emergents (compactus 
Cress., etc. ) well fills tlie seasonal niches available to them. 

Of the Nearctic species many are recorded from only one host 
plant, but considerable field observation is necessary upon most of 
these for which a single plant record exists. However, for several 
species there are abundant data, which imply oligolectic tendencies. 



Revision of the Bee Genus Colletes 163 

I am reasonably certain that the species C, aestivaUs Patton and C. 
andrewsi Cockerell are oligolectic on the flowers of Heuchera spp., 
as they have been taken only from H. americana and H. hispkhi. 
Several listed below are also considered oligolectic until subsequent 
collection infonnation proves otherwise, 

C, albescens Cresson on Ainorpha; C. distinctus Cresson on Ilex; 
C, Qchraceiis Swenk on Eriogonum; C. ivUmattae Cockerell on 
PetaJostemoii; C. saritensis Stephen on Dalea. 

Otl)er species exhibit preference for one or more families of 
flowers, but the great majority are polylectic, deriving their food 
from a variety of unrelated plants. 

The knowledge of the parasites of Nearctic Colletes is very 
meagre J and only a few records are found in the literature. Parker 
and Boving's (1924) paper on the life history of Tricrania sanguini- 
pennis on C. rufifhorax is unique in this phase of Colletes biology. 
The principal parasites of Colletes spp. are the bees of the genus 
Epeolus, but so sketchy is the information that no idea exists as to 
the degree of infestation under normal conditions, or any data on 
their biologies. 

Bischoff (1930), reporting on Epeolus spp. in the European 
region, found considerable minor polymorphism among the mem- 
bers of a single species, and says on this topic, "A problem for the 
future will be to ascertain the existing and failing constancy of our 
middle European species to the native hosts and to what extent 
tliese same species can live on different hosts," He is apparently 
uncertain of the cause of the polymorphism, stating, "About the 
minor differences of the individual form, one can be in doubt 
whether it is a question of food or different host species/' Without 
settling the question raised by Bischoff, Noskiewicz, on the basis of 
observation, is of the opinion "that in many cases one and the same 
Epeolus species can have different Colletes species as hosts/' 

In addition to the two genera mentioned above, Blair ( 1920 ) rec- 
ords the following as parasites of C damesaniis Smith: Diptera; 
Bomhylius minor L,, Miltogramma ptmctata Meig.: Coleoptera; 
Meloe: Hymenoptera; Chrysis ctjanea L* 

Claude-Joseph reports Epeloides sp, and Isepeolus sp. as para- 
sites on C, muscidiis Fries e; Isepeolus sp. and Anthrax sp, as para- 
sites on C. laticeps Friese, He also lists Coelioxys as being a general 
parasite of this genus. 



164 The Uni\^esity Science Bulletin 

DISTRIBUTION AND PHYTOGENY 

Generalizatioos and deductions are always subject to criticism 
because of tlieir tentative nature. In the absence of fossils the possi- 
bility is remote that there can be conclusive substantiation for any 
phylogenetic "tree'' rooted beyond the near past. However, the 
accumulation of a multitude of implications, meaningful but far from 
complete, cannot be ignored. An attempt is made to interpret the 
data at hand without resorting to dogmatic conclusions. 

Though some difference of opinion exists concerning the most 
primitive group of apoids, there is little doubt that members of 
ParacoUetini are the progenitors of the Colletini. The present dis- 
tribution of this primitive group is panaustral; they are found in 
temperate South America, Australia, and southern Africa, CoUefes, 
however, is found throughout the world with the exception of 
Australia J suggesting that the genus arose after the submergence 
of the land bridge between Australia and continental Asia, probably 
during the late Cretaceous, This would still have permitted the 
genus to originate in Africa, South America, or at some marginal 
locality of its predecessor, a form presumably similar to ParacoUetes. 

It is frequently possible to ascertain the center of origin of a groups 
with some reliabiHty, from distribution patterns. However, many 
genera display a center of variation and species frequency far re- 
moved from their point of origin. This appears to be the case in 
Colletes^ for though there is a distinct numerical superiority of 
species in western North America, such diversity is also found in 
otlier ai^eas exhibiting similar habitat diversiBcation (Spain, Turke- 
stan), In these areas, the isolation of populations has probably 
resulted in rapid fixation or even in nonadaptive genetic combina- 
tions, which alone w^ould hardly offer suitable evidence from which 
one could determine a generic center. 

The following text includes 108 species and subspecies, the great 
majority of which are restricted to continental America north of 
Mexico, Eleven species are known to extend into Mexico, but 
furtlier collections should reveal upwards of 45 species or subspecies 
occurring in both the United States and Mexico, Only one species 
is suspected to be common to the Palearctic and Nearctic regions. 
This species, C impunctatus Nylander, is found across the northern 
portions of Asia and Europe, whereas its Nearctic counterpart, C. 
imptmciatus lacnstris Swenk, appears to be restricted to the Hud- 
sonian and Canadian zones of America. Further consideration is 
given the problem later in the text. 



Revision of the Bee Genus Colletes 165 

Adhering closely to distributional patterns of many other Nearctic 
insects, the species of Colletes are most abundant in the diversified 
habitats west of tlie 105th meridian. Of the 108 species, 72 are 
known to occur in this region, approximately 55 being restricted 
to it. I believe that the majority of species of tliis region, certainly 
the daleac and consors groups, either arose in this region or resulted 
from a northward migration of parental stock from the Mexican 
Plateau at some time during the Tertiary, 

Noskiewiez' illustrations of the seventh ventral plates of Palearctic 
Colletes show less diversification of basic form than exhibited by 
Nearctic species; and the derivation of the Palearctic fauna, treated 
by him, from Nearctic sources is well within the realm of probability. 
He states; "According to our present knowledge it appears that the 
genus Colletes is much stronger in Asia than Europe or Africa, Of 
the 123 species worked by me, 54 are purely Asiatic, 20 European, 
15 North African: 19 species are Eurasian, 6 Eurafrican, 8 occur in 
Europe, Asia and Africa and only one species is found exclusively 
in Africa and Asia. If diese numbers are totalled we have 82 
[species] in Asia^ 53 in Europe and 30 in North Africa/' The 
progressive numerical decrease in species number and the reduc- 
tion in morphological comj>lexity as one retreats from North America 
towards Africa lend additional weight to the claim for a New World 
origin of the genus. 

On the same topic it is interesting to note that the nigricons 
group ( Noskiewicz ) , which predominates in the Mediterranean 
regions, has undergone a tremendous reduction in morphological 
complexity, particularly in the copulatory structures of the male: 
the volsellae ( fig. 1, plate XIV, Noskiewicz ) appear to be absent but 
are probably greatly reduced; the gonocoxites are simple, composed 
of what appears to be an uninterrupted segment; the gonostyli are 
broadly fused to the gonocoxites with no evident line of separation 
and the seventh ventral plates of the metasoma are weakly lob ate, 
lacking the complexities of the more primitive types • 

This group, including all species with unsegmented gonocoxites, 
is restricted to the regions about the Mediterranean Sea extending 
from the Canary Islands on the west to Transcaspia on the east. 
It appears to be superimj)osed upon a continuum of diverse species 
having the single common characteristic of segmented gonocoxites. 
Such a localized group evolving towards lines of greatly increased 
simplicity near one of the areas harboring the primitive paracolletine 



166 The University Science Bulletin 

ancestral types would minimize, but not eliminate, the probability 
of African origin. 

There is little doubt in my mind that the major part of the North 
American Colletes fauna originated as siiecessive adaptations of 
Neotropical forms (i*e., americanus^ simalans, latitarsis, consors, 
and daleae groups). Their distribution is largely restricted to 
southern North America. The uniqueness of these groups, the ab- 
sence of close Palearctic relatives^ and the existence of Central 
American relatives contribute to such a hypothesis* 

However, in contrast to these groups there exist groups of related 
forms occurring in both parts of the Holarctic region. The broadly 
distributed species of the inaequalis group in North America (par- 
ticuhirly inaequalis Say and talidus Cresson) have a close morpho- 
logical and biological resemblance to the groups formostis, cariniger, 
and cunicidarius as described by Noskiewicz, [A detailed examina- 
tion of the descriptions of the species in the latter groups as well 
as the illustrations of the seventh ventral plates for each species 
convinces me that Noskiewicz has overemphasized the subdivisions 
at the group level The three groups, comprising a total of five 
species, have a continuous, nonoverlapping distribution from Siberia 
to North Africa; they are, without exception, early spring bees like 
C. inaequalis^ and are very close morphologic ally • It appears that 
he has used single characters of perhaps no more than subspecific 
importance to differentiate groups and even subgenera. For exam- 
ple, the three groups mentioned are separated from a close ally, 
the acutiis group, on the basis of the length of the malar space, 
the color of the hind legs and tarsi, absence of abdominal fasciae, 
and length and density of body pile. I have found none of these 
characters useful except for species separation. C. ctmieidarius, 
which resembles inaequalis most closely, is found from Siberia to 
Germany, its subspecies C c. infuscafus Noskiewicz in Spain and 
Italy; C, formosus Perez is known from Tripoli and Algeria and 
C. cariniger Perez (seventh plates identical with those oi formosus) 
has been taken from Syria and Egypt. In the series of species men- 
tioned there is a progressive loss of the trilobate aspect of the 
seventh ventral plates with the median lobe undergoing greatest 
reduction.] 

If it is assumed that simplicity and reduction are indicative of 
recent origin, inaequalis Say may be considered the most primitive 
species of these groups. Its broad distribution throughout the Ne- 
arctic region, the polylectic habits of the species, and its stabihty in 



Revision of the Bee Genus Colletes 167 

America suggest an invasion of the Palcarctic region probably dur- 
ing Tertiary times, giving rise to the members of the four groups 
hsted above. 

The reverse seems the case with C. impimctQtus lacustris Swenk^ 
occurring in the boreal region of North America, and C. impimc- 
tattis impunctatus Ny lander from Siberia, which are so close mor- 
phologically that I do not hesitate to reduce the former to a sub- 
species of the latter. This distribution, unlike that of the tnaequaUs' 
cunicularius complex, is presently nearly continuous. Here^ how- 
ever, the broad dispersal of forms allied to impiinctatus from 
Switzerland and Sweden to India and Siberia, accompanied by the 
restricted zone occupied by lacustris in North America and its lack 
of close relatives in America^ wovild indicate a migration from 
Eurasia to North America. 

Although I have had little opportunity to examine Old World 
material, T expect that further investigation will reveal that mem- 
bers of the hijalinus group, and possibly others, have Hoi arctic dis- 
tribution and that one or perhaps several independent migrations to 
and from America have taken place during the middle and late 
parts of the Tertiary, 

Nearctic Distribution: The distributional patterns of the genus 
in America are similar to those of a number of other genera. The 
most common of these patterns is exemplified by the two species 
complexes Intzi and consors (maps 6 and 7), which abound in the 
higher altitudes of California, about the northern edge of the Great 
Basin, and along the Continental Divide. No doubt the consors 
group, restricted to a montane habitat, follows the migratory path 
of the Boreal and Transition zones through Colorado and Wyoming, 
whence it skirts the Great Basin to terminate in the Cascades of 
Washington and the Sierra Nevada of central California, On the 
basis of present data hitzi follows a pattern similar to that of 
consors from Colorado to California, 

A third species, htjaUnus Provancher, in which three subspecies 
are recognized, presents a disjunct and confusing pattern. The spe- 
cies, as known to date, occupies the northern plains region of Amer- 
ica and the western lowlands of Cahfornia and Oregon (Map 5). 
To my knowledge, no continuum exists betw^een h, hyalinus, east of 
the Divide, and either h. oregonensis Timberlake or h. gaudialis 
Cockerell on the west, but the resemblance is so apparent that I 
must agree with Timberlake ( 1951 ) when he says, "Renewed study 
of C. hyalinus (sensu stricto) and C, gaudialis convinces me that 



168 The University Science Bulletin 

they are similar enough to be races of one species and the prob- 
ability of iutergradation is enhanced by the presence in Oregon and 
along the coast of northern California of the somewhat intermediate 
form C. h, orego7iensis.'' Records from Matanuska on the coast of 
Alaska and White Horse in the Yukon may prove the species to 
extend up the coast to the north, forming a continuum in the far 
north. Though this is possible, it appears equally probable that 
further collections may reveal a continuous cline to extend through 
a series of river channels and mountain valleys from east to west, 

A fourth pattern, apparent in the distribution of the simulans 
group, is thought to have its stem in Mexico. The northerly migra- 
tion into America follows a three-pronged route from the southern 
Rocky Mountain region: (1) a northerly mountain route into Colo- 
rado and Wyoming, (2) a westerly path into the lowlands of 
Nevada and California, whence it has migrated as far north as the 
valleys of British Columbia, and (3) a broad adaptation to the 
plains regions of America east of the Continental Divide (Map 1). 

The region of origin of the texaniis subgroup is obscure but their 
close relationship to the rest of the consors group would weigh 
heavily in favor of a thesis supporting their derivation from a 
Mexican form simik^r to consors- They are without exception re- 
stricted to the lower Sonoran zone from western Texas to Cali- 
forniap 

m 

A number of distribution maps have been included in the present 
work in an attempt to clarify the ranges of those species in which 
confusion has already arisen or is likely to arise. In most instances 
two or more sibling, or closely related, species have been plotted on 
the same map to illustrate more clearly areas of overlap and limits 
of the ranges. Other maps have been prepared for species in which 
subspeciation has given rise to complex patterns, e. g., simulans 
Cresson, consors Cresson, hyaUntis. Known marginal records have 
been plotted for the more common species. Areas are shaded to 
indicate the recorded as well as suspected range of the group in 
question. 

A similar procedure has been followed in presenting distributional 
data in the text. When the range is broad and material abundant, 
only peripheral localities are noted, but for the less common and 
new species complete collection information is recorded. For the 
most part the two recorded extremes serve to delimit the seasonal 
flight period of the species and where information is available the 
peak of the flying population is noted. 



Revision of the Bee Genus Colletes 169 

GEOGRAPHICAL VARIATION 

The observed details of geographical variation among the various 
species have been recorded under the species. Most of the wide- 
spread species seem to vary to some degree geographically; only 
v^^here the variation is rather obvious and consistent are subspecies 
recognized. In a few instances subspecies are listed that would 
probably not have been recognized except for the fact that names 
had already been applied to them. 

There is no obvious consistent association of the variations with 
geographic or climatic factors. Thus no ecological rules, such as 
those readily devised for coloration, size, and proporations in var- 
ious groups of vertebrates, wasps, butterflies, etc., apply consist^ 
ently to the variations in Colletes. Generally, the populations from 
arid western habitats are paler in ordinary body pile, in tlie pale 
covering of tlie abdomen, and in the wings than their near relatives 
from more humid areas, C. consors mesocopus Swenk and C. 
nigrifrons Titus may be cited as exceptions to this general rule, in 
which paler forms are found in more humid areas. There are, of 
course, a few widespread rather invariable species as well. 

MEASUREMENTS 

Frequent reference is made to the lengths of the antennal or 
flagellar segments in both the descriptions and the keys. Unless 
indicated otherwise, the dorsal surface of any of the medial flagellar 
segments is taken as a standard. 

Considerable difiiculty was encountered in measuring the length 
of the malar space. In all species the width of the malar space is 
the distance between the anterior and posterior mandibular artic- 
ulations. For the most i)art the length is considered to be the dis- 
tance represented by a perpendicular line running from the anterior 
mandibular articulation to the compound eye (Figure 85), How- 
ever, in many species the compound eye is narrowed below, and if 
the malar space is broad this perpendicular line reaches well up 
along the inner orbital margin. In such cases the length is taken 
as the distance between the hne joining tlie mandibular articulations 
and a parallel line running through the niediobasal corner of the 
compound eye (Figure 85). The corner is hardly angulate but 
sharply rounded and distinct. 

Measurements of total length and wing length given in descrip- 
tions are usually means. Extremes are not indicated for they mean 
httle, especially for the body, where much depends on the degree 



170 The University Science Bulletin 

of telescoping of the abdomen. In most species the smallest in- 
dividuals are about 3 millimeters shorter than the largest, 

DESCRIPTION OF THE GENUS 

Swenk ( 1908 ) has given an excellent account of the history of the 
name Collet e$ and of its genotype (C. siiccinctus Linnaeus), and 
Griffin (1935, 1938) has verified information on the dating of the 
principal works involved. 

The subgenera proposed by Cockerell, Friese, and Noskiewicz are 
for single species or very small groups (up to 3 species) which are 
aberrant in certain respects. In no way do they represent major 
divisions of the genus into its principal phyletic lines ^ but rather 
are names provided for unusual terminal branches of these lines. 
As yet the phylogeny of the genus as a whole has not been suffi- 
ciently elucidated to make recognition of the principal lines of 
descent possible. Until this is done, it seems best to synonymize 
the subgeneric names. 

CoUetes Latrcille, 1802, Histoire naturclle des foumiis, p. 423. 

Type: Apis snccincta Linnaeus. Monobasic. 
Evoaia Panzer, 1806, Krit. Rev. Insektenfauna Deutschlands, vol, 2, p. 207, 

Type: (Apis calendarum Panzer) =: Api6' succincta Linnaeus. Monobasic. 
CoUetes subg, RhijwcoHetes Cockerell, 1910, Entomologist, vol. 43, p. 242, 

Type: CoUetes nasutus Smith. Monobasic. 
CoUetes subg. Ptilopoda Friese, 1921^ Stettiner Ent. Zeitung, vol. 82, p. 83. 

Type: (CoUetes macuUpennis Fiiese) ■=• CoUetes spUoptera Cockerel!, 

Monobasic. 
CoUetes subg. DenticoUetes Noskiewicz, 1936, Prace Nauk. Wydawnictwo 

Towarzystwa Nauk, Lwow^ie, scr. 2, vol* 3, p. 486* 

Type: CoUetes graeffei Alflcen. Monobasic. 
CoUetes subg. PuncticoUetes Noskiev^icz, 1936, Prace Nauk. Wydawnictwo 

Towarzystwa Nauk, Lwowie, ser, 2, vob 3, p. 490. 

Proposed without genotype designation and therefore invalid under article 

25 C of International Rules of Zoological Nomenclature. 

Head and thorax witli pile long and dense; metasomal terga 
usually fasciate; posterior femora of female with long dense pollen 
brush; labrum broader than long with median concavity, often de- 
limited by thickenings on either side; subantennal sutures directed 
towards inner margins of antenna! sockets; facial foveae present, 
most evident in female, of variable width, nonpilose and depressed; 
galeae short; submentum broad and elongate; labial palpi short, 
4-segmentedj first segment VA times as long as second, others sub- 
equal; glossa shortj broad, bifid, strongly emarginate medially; 
maxillary palpi 6-segmented; eyes concave along inner orbital mar- 
gins; pre-episternal sutures complete; metanotum horizontal, in 
same plane as scutellum and basal area of propodeum; propodeum 
with narrow horizontal basal area, smooth or longitudinally carinate^ 



Revision of the Bee Genus Colletes 171 

posterior face with a 3-coriieredj shiny, depressed, nonpliimose me- 
dian area, pointed below; wings hairy; pterostigma hirge; marginal 
cell with apex not on wing margin; fore wings with three sub- 
marginal cells, first equal to second and third together in lenii;th, 
second and third subequal in length; vein second m-cu at right 
angles to Cui and strongly arcuate outward in posterior portion; 
pygidial and basitibial plates absent; inner hind tibial spurs strongly 
toothed or combed; eighth metasomal (ninth abdominal) sternum 
of male roughly equilaterally triangular; capsule with gonocoxites 
usually transversely divided (always in Nearctic species); gonostyli 
usually distinct and pilose apically; gonobase large; penis valves 
enlarged basally, tapered apically with dorsal and/or ventral 
"wings'"; volsellae large and distinct (in Nearctic species), 

GROUPINGS WITHIN THE GENUS 

The morphological uniformity of the genus indicates no obvious 
major phyletic lines of descent; however ^ a number of small aberrant 
groups are readily recognizable. To facilitate the separation and 
treatment of the members of the genus, tlie species were placed in 
natural groups and the groups arranged consecutively in what ap- 
pears to be a phyletic order of descent. 

It is difficult to outline briefly the basis of these divisions, for a 
multitude of characters are concerned and the resulting group char- 
acters would tend to be as exhaustive as the species descriptions* 
The princii>al factor influencing the assignment of the species to a 
group was the structure of the male genitalia; this includes the form 
of the seventh ventral plates, size and shape of the gonostyli, struc- 
ture of the penis valves and wings, and shape of the gonocoxites. 
Secondary group characters include the size of the flagellar seg- 
ments, size and structure of the clypeus, presence of metapleural 
prominences, body puncturation, etc* At times one or two char- 
acters are sufficient in separating the groups, but for the most part 
a consideration of the general body morphology is necessary. Be- 
cause of the last-mentioned point it is believed that the compre- 
hensive treatment necessary for characterizing the groux>s that follow 
would not add appreciably to the context. 

Groups I to XVI are composed of several closely-related species, 
and groups XVII to XIX are each represented by a single species. 
The latter three groups are strongly divergent and show little re- 
semblance to any of the groups preceding them. It mii^ht have been 



172 



The University Science Bulletin 



covered. For the sake of uniformity this w^as not donej and the 
groups are listed in the order of their appearance in tlie text. A 
desirable feature would have been a key to the groups. This^ how- 
ever, would have been unsatisfactory from the standpoint of species 
separation, for in the vast majority of cases there were no obvious 
group characters that could be directly applied to a workable key. 
I feel that such a key would add to the complexity rather than ease 
the burden of determination. 

The groups and their component species are as follows ; 

Group I productus 



prodiictus Robertson 
arizonensis Stephen 
cercidii Tiniberlake 
Ttidis Timberlake 

Group II compactus 
compactus Cresson 

Group III latitarsis 
lafitards Robertson 

Group IV^ simidans 
simidans Cresson 
angelicus Cockerel! 
fulgidiis Swenk 
Tufocinctus Cockerell 
louisae Cockerell 
bryanti Timberlake 
birkmanni Sweiik 

Group V aestivalis 
aestivalis Fatten 

Group VI robertsonii 
rohertsonii Dalla Torre 
metzi Timberlake 
timberlakei Stephen 

Group VII nudus 
nudiis Robertson 
carolimis Mitcliell 

Group VIII americanus 
americaniis Cresson 
annae Cockerell 
laticinctus Timberlake 
hradlcyi Mitchell 
mitchelli Stephen 
ochraceus Swenk 
tectiventris Timberlake 
gypmcolens Cockerell 
albescens Cresson 

Group IX hijalinus 
hijaUnus Provancher 
lutzi Timberlake 



perileucus Cockerell 
gilensis Cockerell 
skinneri Viereck 
vandykei Timberlake 



punctipennis maurus Stephen 

slevini Cockerell 
eulophi Robertson 
kincaidii Cockerell 
trigonatus Cockerell 
utiUs Cockerell 
delodontus Viereck 
tvootoni Cockerell 

andrewsi Cockerell 

larreae Timberlake 
furgiventris Timberlake 
kansensis Stephen 

brimleyi Mitchell 



aberrans Cockerell 
howardi Swenk 
susannae Swenk 
saritensis Stephen 
thysaneUae Mitchell 
wilmattae Cockerell 
fnicheneri Stephen 
mandibuJaris Smith 
soUdaginis Swenk 

distinctus Cresson 
phaceliae Cockerell 



Revision of the Bee Genus Colletes 



173 



validus Cresson 



brevicornis Robertson 

wickhami Timberlake 
chamaesarachae Cockerell 
scopiventer Swenk 
texdiius Cresson 
swenki Stephen 
linsleyi Timberlake 



bulbotibialis Stephen 
ciUatoides Stephen 



deserticola Timberlake 
petalostemonis Swenk 
prosopidis Cockerell 
solifantis Timberlake 



Group X inaequalis 

inaequalis Say 

thoracicus Smith 
Group XI impunctatus 

imptmctatus htcustris Swenk 
Group XII wilUstoni 

wiUhioni Robcrts;on 
Group XIII consors 

consors Cresson 

paniscus Viereck 

nitesccns Timberlake 

californicus Provancher 

nigrifrons Titus 

xerophihis Timberlake 

sphaeralceae Timberlake 
Group XIV intermixtus 

intermixtiis Swenk 
Group XV ciliatus 

ciliatus Palton 

heamerorum Stephen 
Group XVI daleae 

dalecie Cockerell 

algarohiae Cockerell 

clypconitens Swenk 

coviUeae Timberlake 

salicicola Cockerell 
Group XVII aridus 

aridus Stephen 
Group XVIII titusensis 

titusenms Mitchell 
Group XIX longifacies 

longifacies Stephen 

KEY TO THE MALES 

To facilitate the separation of the species, three of the most dis- 
tinctive natural groups are removed in the first three couplets. It 
would have been desirable to separate each of the nineteen grc'jps 
in this manner^ but this proved impractical, for there are no dis- 
tinctive characters applicable to all of the species within each gr^^^ip. 

Couplets 1, 2, and 3 require some explanation, as many of *^he 
species of these large natural groups (americantis group, consors 
group, and daleae group ) removed by these couplets are not always 
recognizable by one or two obvious characters. Unfortunately, in 
both keys several species that have a striking resemblance in the 
critical key characters have been taken out with the americanus 
and consors groups, although they are not members of tliese groups. 
This was done to facilitate the sex>aration of species in which key 



174 The University Science Bulletin 

characters are likely to be confusing* It should be noted that all 
species foieiga to but occurring in the couplets stated to be mem- 
bers of the americanus or consors groups are also found elsewhere 
in the key. The following explanatory material is therefore pro- 
vided: 

Forms which should go to couplet 70 ( americanus group ) exhibit 
the following characters: malar spaces no longer than broad; flagel- 
lar segments one and one-quarter to one and three-quarters times 
as long as broad; clypeus uniformly curved and densely punctate 
with striate or ovate punctures; propodeum with the later oposterior 
margins abrupt or ridged, not rounded; pile of body all light; 
seventh ventral plates with discs quadrate to weakly triangular- 
penis valves with narrow ventral wings; gonostyli short, triangular. 

Forms which should go to couplet 88 (consors group) exhibit the 
following characters; malar spaces no longer than seven-eighths as 
long as broad; flagellar segments short, about as long as broad; 
propodeum with basal area narrow and sloping rather sharply 
ventrally, lateral and posterior faces finely striate and roughened, 
rounded at lateroposterior margins; pile of body long and dusky 
grey, often intermixed with black on head and thorax; seventh 
ventral plates roughly quadrate, or reduced to short transverse 
discs; penis valves with broad dorsal and ventral wings; gonostyli 
short, roughly triangular. 

Forms which should go to couplet 108 (daleae group) exhibit 
the following characters: malar spaces at least as long as broad; 
flagellar segments at least as long as broad; clypeus elongate with 
longitudinal median sulcus bordered by lateral shiny, sparsely 
punctate rims; sulcus densely punctate, rims sparsely punctate with 
round punctures; propodeum with basal area smooth and broad, 
usually not sharply pitted but with a few weak longitudinal rugae, 
lateral and posterior faces shiny with numerous fine punctures; body 
covered with long white pile; species all small, less than 9 mm. in 
length, found only in western part of the Great Plains and Lower 
Sonoran zone of North America; seventh ventral plates quadrangular 
or weakly modified to triangular, discs covered with fine short pile; 
penis valves with only ventral wings, wings small; gonostyli virtually 
absent, evident as slightly expanded apical processes* 

1. Metapleura each with dorsal prominence or horizontal carina, 

usually with testaceous rim, and malar spaces no longer than 

broad ( Flagellar segments longer than broad ) 70 

Aletapleura with no dorsal prominence or if weakly prominent 
with carinae curving vcntrally well in front of posterior 



Revision of the Bee Genus Colletes 175 

margins, if having rimmed prominence then malar spaces 
one and one-half times as long as broad _ , 2 

2{1). Median flagellar segments usually as long as broad or slightly 

longer, and penis valves with broad dorsal and ventral wings, 88 
Median flagellar segments usually at least one and one-half 
times as long as broad; if shorter, penis valves lacking 
dorsal wing ........,._ 3 

3(2)- Clypeal punctures sparse and round and clypeus with longi- 
tudinal median sulcus; propodeum with basal area broad 
and smooth, occasionally with a few weak longitudinal 

Clypeal punctures elongate, at least apically, or, if not, clyi>eus 
without any indication of a sulcus; propodeum with basal 

area deeply pitted 4 

4(3). Mesoscutum, seutellumj or inner orbital margins with varying 

amounts of black pile ...._.. 5 

Mesoscutunij seutcllum, and inner orbital margins with pile 

5(4). Malar spaces at least as long as broad, usually longer. ..,.,_ 6 

Malar spaces no longer than three f ourtlis as long as broad 12 

6(5), Malar spaces at least one and three-fourths times as long as 

broad; mesepisterna dull and roughened ( Prothoracic spines 
absent) . , ,,.....,,... validus 

Malar spaces less than one and one-half times as long as broad; 

mesepisterna punctate with shiny interspaces 7 

7(6). Metasomal sterna two to four emarginate medially; pile of body 

dusky; malar spaces slightly longer than broad (Tergal 
fasciae very weak and dusky) . . _ . .impunctatus lacustris 

Metasomal sterna two to four with posterior margins entire; 
pile of body white to tawny; malar spaces one to one and 

one-half times as long as broad . . . _ _ . _ . _ 8 

8(7). Mesepisterna dull and roughened, obscurely punctata . 9 

Mesepisterna coarsely punctate with shiny interspaces 10 

9(8). Propodeum with posterior face outside of triangle rugose above; 

metasomal terga with discs having abundant short, erect, 
black pile; thorax with pile long, dense, and ochreus; seventh 
ventral plates with lateral lobe short and at times partially 
fused to median (fig. 56) , thoracicus 

Propodeum with posterior face outside of triangle dull and 
roughened; metasomal terga with discs having pile white to 
pale grey; tliorax with pile long, fine, and pale grey on 
periphery; seventh ventral plates tripartite apically^ lateral 
lobes long and broadly separated from median lobe (fig. 

55 ) , Inaequalis 

10(8), Inner orbital margins with admixture of black pile (Malar 

spaces one and one-quarter times as long as broad; clypeus 
with deep median longitudinal sulcus and impunctate lateral 
rinis) , ,.._,... .compactus 

Inner orbital margins with pile all light .._... II 



176 The University Science Bulletin 

11(10), Malar spaces one and three-eighths times as long as broad; 

seventh ventral plates laterally quadrate with long latero- 
basal *'taiF and distinct neck ( 6g. 7 ) ( Metasomal terga one 
and two coarsely and densely, almost contiguously, punc- 
tate) ..,..., . .skinneri 

Malar spaces as long as broad; seventh ventral plates longi- 
tudinally quadrate^ lacking necks between discs and articu- 
latorj^ condyles, discs about twice as long as broad (fig. 19), 

brfjanti 
12(5), Posterior basitarsi shorty no more than two and one-half times 

as long as proaci . ^ ., ^ ,< ««,.».»«««,».,.,..........., , Lo 

Posterior basitarsi about four times as long as broad , . . . 15 

13(12). First metasomal tergum shinyj weakly folhculated (with a dis- 
tinct metallic blue lustre); posterior basitarsi two and one- 
half times as long as broad . . , , intermixtus 

First metasomal tergum densely punctate with shiny inter* 
spaces J punctures about one puncture width apart; posterior 

basitarsi two times as long as broad 14 

14(13). Wings pictured; neotropical, reaching southern Texas, 

pimctipennh maurus 

Wings not pictured; American Great Plains . latitarsis 

15(12). Dorsolateral fringes of propodeum with strong admixture of 

black pile .._....._ 16 

Dorsolateral fringes of propodeum with pile all light. 17 

16(15). Length 8.5 mm.; mesepistema with pile exclusively light; 

metasomal tergum one sparsely and finely punctate on an- 
terior median face , . , . . . arizonensis 

Length 13.5 mm.; mesepisterna with abundant black pile on 
upper faces; metasomal tergum one uniformly densely punc- 
tate, punctures no more than one puncture width apart^ 

vandykci 
17(15), Prothoracic spines long and sharp j at least as long as width 

across bases . . , « . 18 

Prothoracic spines short, vestigial or obliquely truncate. ...... 24 

18 (17), Vertex and mesoscutum witli abundant black pile; length 11-14 

mm. ( Body coarsely punctate) . 19 

Vertex with pile all light; mesoscutum with but few black hairs; 

19( 18), Metasomal tergum two with sharp basal depression; metasomal 

tergum one deeply, almost contiguously, punctuate; clypeus 

striately punctate with shiny interspaces . gileims 

Metasomal tergum two not depressed basally; metasomal ter- 
guni one shiny, punctures deep but separated by at least 
one and one-half puncture widths; clypeus deeply, con- 
tiguously punctate with no shiny interspaces nudus 

20(18), Propodeum with posterior face shiny, striately rugose, forming 

deep pits dorsally outside of triangle; seventh ventral plates 
with discs twice as broad as long, apices broadly concave 
(fig, 33 ) . . . , caroUnus 



Revision of the Bee Genus Colletes 177 

Propodeum with posterior face dull and roughened or smooth 
and shiny; seventh ventral plates with discs at least as long 
as oroaci ,.,,.,, Ai 

21(20), Propodeum with basal area flat and smooth with few longi- 
tudinal rugae, not at all quadra tely pitted; metasomal tcrgum 

one sliiny^ impunctate . . , . , , , perileucus 

Propodeum with basal area deeply quadrat ely pitted; metasomal 
tergum one finely punctate 22 

22(21), Metasomal tergum one finely and sparsely punctate, punctures 

one and one-half to two puncture widths apart; seventh 

ventral plates short, roughly triangular (fig, 51) hyalinus 

Metasomal tergum one coarsely and densely punctate, punctures 
no more than one puncture width apart; s<-\Liith ventral 
plates elongate, at least twice as long as broad, quadrate, . . . 23 

23(22), Penis valves with ventral wings truncate apicallyj coterminal 

with valve apices; seventh ventral plates quadrate with api- 
cal margins strongly expanded^ almost lobate (figs. 12, 13, 

Penis valves with ventral wings narrowed apically, weakly 
pointed; seventh ventral plates quadrate witli apices broadly 
rounded, not lobate (fig, 16) fnlgidus 

24(17). Prothoracic spines obliquely truncate with posterior margins 

extending beyond anterior (Second metasomal tergum with 

weak basal fascia ) .....,.,. angeUcus 

Prothoracic spines short or absent, not truncate 25 

25(24). Propodeum with posterior face shiny, striately rugose, forming 

deep pits dorsally outside of triangle . , . , , 26 

Propodeum with posterior face dull and roughened, not striate 
or pitted outside of triangle 27 

26(25), Seventh ventral plates laterally extended, median and lateral 

margins strongly reflexed; discs of plates about twice as 
broad as long (fig. 33); malar spaces three-quarters as long 

as broad , , . . carolinus 

Seventh ventral plates elongate, at least twice as long as broad 
with strong laterobasal projections (fig, 16); malar spaces 
five-eighths as long as broad. . , , Julgidus 

27(25), Mesepisterna dull and roughened, punctures obscure; sternal 

fasciae weak and incomplete inaequalis 

Mesepisterna coarsely punctate with shiny interspaces^ pimc- 
tures about one-half puncture widtli apart; stcnial fasciae 
complete, dense, and white . . , 28 

28(27). Propodeum quadrately pitted with deep shiny pits outside of 

triangle; black pile restricted to a few black hairs on sou- 
tellum; mesepisterna weakly rugosely punctate; seventh 

ventral plates roughly quadrate (fig, 4) . .rudis 

Propodeum with basal area smooth, not pitted outside of tri- 
angle; black pile abundant on mesoscutum and scu tellum; 
niesepisterna coarsely punctate with shiny interspaces; sev- 
enth ventral plates broadly triangular with apical margins 
broadly rounded ( fig* 3 ) , . . . .,.,.. , cercidii 



178 The University Science Bulletin 

29(4), First metasomal tergiim shinyj impunctate, or, if punctate, with 

a few scattered folliclelike punctures especially laterally .... 30 
First metasomal tergum closely punctate, punctures no more 

than two puncture widths apart . . . . 42 

30(29). Eyes with inner orbital margins nearly parallel {Mesepistema 

and metasomal terga dull, obscurely punctate) 31 

Eyes with inner orbital margins strongly convergent below 
(First flagellar segment no more than one-half as long as 

second ) 32 

31(30), Posterior basitarsi very long and broad, about two and seven- 
eighths times as long as broad; pro thoracic spines absent; 

length 13-15 mm ,,,.,,,... andrewsi 

Posterior basitarsi long and narrow, about four times as long as 
broad; prothoracic spines short and sharp; length 11- 

12 mm aestivalis 

32(30), Malar spaces at least as long as broad. . 33 

Malar spaces shorter, no more than three-quarters as long as 

broad 34 

33(32). Metapleura protuberant above with narrow black rim; pro- 

podeum coarsely rugose with large pits on posterior and 
lateroposterior faces outside of triangle ............ producius 

Metapleura not protuberant above; propodeum finely rough- 
ened, not pitted outside of triangle , JiyaUnus 

34(32), Prox)odeum coarsely rugose^ roughened, forming large pits on 

upper posterior face outside triangle; mesepistema coarsely 

nigosely punctate , .....,, 35 

Propodeum finely roughened or smooth outside triangle, never 
pitted; mesepistema deeply punctate with shiny interspaces, 37 
35(34). Flagellar segments shorty as long as broad; malar spaces 

hnear .*,.,., titusensis 

Flagellar segments about one and one-half times as long as 
broad; malar spaces at least three-eighths as long as broad, 36 
36(35), Malar spaces three-fourths as long as broad; seventh ventral 

plates with discs broader than long, weakly quadrate (fig. 

34 ) . brlmletji 

Malar spaces three-eighths as long as broad; seventli ventral 
plates longer than broad, roughly triangular (fig. 53), distinctus 
37(34). Flagellar segments about as long as broad (Seventh ventral 

plates with discs transverse and narrow^ sharply excavated 

apically (fig. 75) ) aridus 

Flagellar segments at least one and one-half times as long as 

broad ..,..,... » ^ . . 38 

38(37), Penis valves with broad dorsal and ventral wings; seventh ven- 
tral plates elongately rectangular^ twice as long as broad 

{ fig. 67 ) . . ^ wickhami 

Penis valves lacking dorsal wing; seventh ventral plates never 

longer than wide . . . , . , 39 

39(38), Prothoracic spines short or vestigial; nervures light brown; 

length 11-14 mm. 40 

Prothoracic spines sharpy at least as long as width across base; 
nervures dark brown to black; length 8.5-9.5 mm 41 



Re\t[Sion of the Bee Genus Colletes 179 

40(39), Malar spaces two-thirds as long as broad; metasomal terga im- 

punctate larreae 

Malar spaces one-half as long as broad; metasomal terga with 

sparse coarse punctures turgiventris 

41(39). Propodeum with basal area deeply quadrately pitted; meta- 
somal tergum one sparsely punctate; terga shiny black; 
metasomal fasciae weak and narrow; head and thorax with 

pile fuscous and sparse ( Length 8.5 mm. ) hyalinus 

Propodeum with basal area nearly smooths not pitted; meta- 
somal tergum one impunctate; terga shiny 1:>lue-back; meta- 
somal fasciae dense and white; head and thorax with pile 

wliite perileuciis 

42(29), Malar spaces linear to one-fourth as long as broad; metasomal 

terga closely, often contiguously, punctate to lateral mar- 
gins (Apical fasciae in abrupt declivous depressions) ...... 43 

Malar spaces at least one-third as long as broad; metasomal 

terga variable, never contiguously punctate 47 

43(42). Prothoracic spines at least as long as width across base; pile of 

head and thorax long and white; metasomal tergum one 

coarsely punctate 44 

Prothoracic spines short or absent; pile of head and thorax 
short, dense J and tinged with ochreus; metasomal tergum 

one very finely punctate , . 46 

44(43)* Seventh ventral plates transverse, apical margins broadly ex- 
cavated and fringed with longj light ochreus pile (fig. 27), 

robertsonii 
Seventh ventral plates with apical margins expanded or com- 

45(44). Seventh ventral plates with basal portions transverse as in 

robertsonii but with transverse lobes attached to medio- 

apical processes ( fig, 30 ).._,,.,_,._, , .._.... metzi 

Seventh ventral plates with apical margins expanded, tending 
to membranous, plates roughly quadrate, narrowed later- 
ally (fig. 31 )-,......>... ..,.,. timberlakei 

46(41). Mesepistema dull, shallowly obscurely punctate^ especially be- 
low; seventh ventral plates fully semilunar (fig. 72); tegulae 
light hyaline; penis valves with ventral membranous wings 

absent except for small preapical piece ciliafus 

Mesepistema distinctly punctate with shiny interspaces; seventh 
ventral plates narrowed, almost sickle-shaped (fig. 73); 
tegulae deep brown; penis valves with broad ventral wings, 

beamerorum 

47(42). Posterior basitarsi short, about two and three-fourths times as 

long as broad and curved longitudinally; posterior tibiae ex- 
panded medially^ constricted towards base and apex (Cly- 
peus long, flat, shiny, sparsely and finely punctate; seventh 
ventral plates roughly triangular v^ith apices sharply emar- 

ginate (fig, 71 ))..... , , bulbotibialis 

Posterior basitarsi at least three and one-half times as long as 
broad and straight; posterior tibiae not constricted apically, 48 



180 The University Science Bulletin 

48(47). Metasomal tcrgum two uniform from base to apex, not de- 

pxcssstQ- Dasaiijf **,,,»,*,,,.« ,,»*i ^u 

Metasomal tergum two depressed basally, with or without basal 

49(48). Mesoscutum and scuteUum with dense covering of ochreus to 

yellow pile, obscuring surface; mesepistema dull, rough- 
ened; malar spaces three- fourths as long as broad .... thoracicus 
Mesoscutum and scutellum with pile white to tawny; mes- 
epistema coarsely punctate with shiny interspaces; malar 

spaces one-half as long as broad turgiventris 

50(48). Malar spaces at least seven-eighths as long as broad. ........ 51 

Malar spaces no more than three-fourths as long as broad 60 

51(50), Metasomal tergum one with punctures deep, punctures about 

one puncture width apart or less 54 

Metasomal tergum one with pimctures fine^ shallow, and sepa- 
rated by at least two puncture widths . . . 52 

52(51). Prothoracic spines sharp, length at least one and one-half 

times width across base , . 53 

Prothoracic spines short, triangular (Wings whitish hyaline; 
seventh ventral plates with discs cordate and w^ith latero- 
basal projection at bases of discs and necks (fig, 18)) . . .louisae 
53{52), Seventh ventral plates as long as broad, roughly triangular; 

gonostyli about as long as width across base (fig* 51) hyalmus 
Seventh ventral plates with discs twice as long as broad, 
roughly quadrate with lateral margins broadly rounded; 
gonostyli two and one-half times as long as broad (fig. 21), 

sJevini 

54(51). Malar spaces long, about one and one-fourth times as long as 

broad ( Metasomal terga with discs covered with white or 

light-grey pile; tegulae light ochreus hyaline) wootoni 

Malar spaces about as long as broad^ or shorter . 55 

55(54), Seventh ventral plates short and broad, about as broad as long; 

gonostyli no longer than broad _.,,.,. 56 

Seventh ventral plates at least twice as long as broad; gonostyli 
two and one-half times as long as broad 58 

56(55). Malar spaces as long as broad; metasomal tergum two strongly 

depressed basally with weak basal fascia (Seventh ventral 
plates with discs slightly broader than long, surface with 
imif orm covering of fine pubescence ( fig. 54 ))..... . phaceliae 

Malar spaces no longer than three-fourths as long as broad; 
metasomal tergum two with no basal fascia , , , . ^ . ^ ^ 57 

57(56), Length 8 mm.; body densely covered with long wliite pile; 

seventh ventral plates with lateral hair bands strongly de- 
veloped and broadly united to median band basally (fig, 

51 ); lowland species hyalmus 

Length 7 mm.; body with pile sparse and grey; seventh ven- 
tral plates with lateral hair bands weakly developed, not 
broadly united to median band basally, pile of lateral bands 
short (fig, 52); montane species, Autzi 



Revision of the Bee Genus Colletes 181 

58(55). Seventh ventral plates witli distinct petiolatc necks between 

discs and articulatoiy condyles , , . 59 

Seventh ventral plates lacking necks between discs and condylar 
articulations, discs broadly united to condyles (fig, 19) 
( Mesepisterna densely, coarsely, contiguously punctate 
above; body with pile usually strongly tinged with och- 
reus ) - . . ...„.,. , . , bnjanti 

59(58). Seventh ventral plates with abrupt lateral shoulders at latero- 

basal margins of discs^ strongly emarginate beneath (fig, 

23 ) ..,.,..... kincaidii 

Seventh ventral plates uniformly curved about lateral margins 
of discs ( fig, 22 ) , eulophi 

60(50), Seventh ventral plates with discs as broad as long; gonostyli 

short, no more than one and one-half times as long as width 

across the bases , . . , , - . . 61 

Seventh ventral plates witli discs twice as long as broad, 
roughly quadrate; gonostyli long and slender ^ two and one- 
half times as long as width across base , 64 

61(60), Malar spaces one-third as long as broad; penis valves with 

narrow dorsal wings; gonostyh broader than long (fig. 74), 

ciliatoides 

Malar spaces at least one-half as long as broad; penis valves 
with no dorsal wings; gonostyli about one and one-half 

times as long as broad . . . , 62 

62(61). Metasomal tergum two with weak basal fascia; seventh ven- 
tral plates with discs slightly broader than long, lateral mar- 
gins broadly rounded, discs with uniform covering of fine 

pubescence (fig, 54 ) . . ^ phaceliae 

Metasomal tergum two with no basal fascia; seventli ventral 
plates with discs roughly triangular, lateral margins straight, 
• discs with pile most dense along lateral and median mar- 
gins ._........, 63 

63(62). Body densely pilose with long white pile; seventh ventral 

plates with lateral hair bands well developed and broadly 
united to median bands basally, pile of lateral bands long 

( fig. 51 ) ; lowland species _.........,. hyalinus 

Body with pile sparse and tawny to white; seventh ventral plates 
with lateral hair bands weakly developed, not united to me- 
dian band basally, pile of lateral bands short {fig, 52); 

montane species ......,, lutzi 

64 (60), Prothoracic spines vestigial, triangular or obhquely truncate at 

apex .......,.,,.. 65 

Prothoracic spines long and sharp, at least as long as width 

across base * ■■ - 69 

65(64). Protlioracic spines obliquely truncate with posterior margins 

extending beyond anterior (Metasomal tergum two with 
weak basal fascia; seventh ventral plates with strong latero- 

basal projections (fig, 13) ) < angeUcus 

Prothoracic spines sharply pointed or vestigial, . , . , 66 



182 The University Soence Bulletin 

66(65). Malar spaces three-fourths as long as broad; wings whitish 

hyaline with httle pubescence; metasomal tergum one with 
few coarse punctures, at least two puncture widths apart 
on disc (Seventh ventral plates with long necks between 
discs and condyles, discs cordate with later obasal projec- 
tions at junction of discs and necks ( fig. 18 ) ) . louisae 

Malar spaces less than five-eighths as long as broad; wings 
dusky with abundant testaceous pubescence; nietasomal ter- 
gum one distinctly punctate with punctures one and one- 
half puncture widths apart . * . 67 

67(66). Seventh ventral plates elongate, roughly ovate with short neck 

and lacking laterobasal projection (fig. 20) ... .birkmanni 

Seventh ventral plates elongate, roughly quadra te^ with no 

neck between discs and condyles 68 

68(67). Metasomal tergal discs four to six with long, erect^ light pile; 

nietasomal terga one and two with apical fasciae narrow 
and weak; seventh ventral plates lacking laterobasal projec- 
tions ( fig. 17 ) .... * Tufocincfus 

Metasomal tergal discs four to sk with erect fuscous to black 
pile; metasomal tcrga one and two with apical fasciae broad 
and dense; seventh ventral plates with strong laterobasal 

projections (fig* 16) fulgidus 

69(64). Seventh ventral plates elongate, roughly ovate, weakly shoul* 

dered but with no laterobasal projections ( fig, 20 ) . , . , hirkmanni 
Seventh ventral plates elongate, roughly quadrate, expanded 
apically with strong laterobasal projections (figs. 12, 13, 14), 

simulans 
70(1), Lower edge of nietapleural prominence with a broad rim 

which hangs down and obscures surface beneath it in 

A tl L %^ -L ^^ J%. VI. *^ W n*i'*i*irH*w*Mkam-**-t ■■■ ■■■'■.•.■a m a J. M. u ^ -.^+#..| , if %^ 

Lower edge of metapleural prominence weakly protuberant 

with a narrow rim which projects laterally . , . 71 

71(70). Seventh ventral plates transverse, narrow, with long, dense 

apical fringe of fuscous pile (fig. 29); tegnlae black; meta- 
pleural prominence abrupt^ heavily rugose including rim, 

kansensis 
Seventh ventral plates roughly quadrate in form; tegulae light 
brown hyaline; nietapleural prominence weakly protuberant, 

not rugose ...,_._ 72 

72(71). First metasomal tergum impunctate or weakly punctate medi- 

nllv 7*^ 

First nietasomal tergum densely punctate ( Malar spaces three- 
fourths as long as wide; abdomen and thorax with pile 

dusky to yellow; length 10-11 mm,) howardi 

73(72). Vertex and mesoscutum with admixture of black pile; hypoepi- 

meral area abniptly protuberant; flagellar segments short, 

about as long as broad thysanellae 

Vertex and mesoscutum with pile all light. ..,.,..... 74 



Revision of the Bee Genus Colletes 183 

74(73). Malar spaces three-fourths as long as broad; body covered with 

long, dense, white pile; seventh ventral plates quadrangular, 
weakly rounded laterally (fig. 40); length 9-10 mm., gypsicolens 
Malar spaces one-third as long as broad; body covered with 
short, sparse, dusky pile; seventh ventral plates almost 

square ( fig. 58 ) ; length 7-8 mm , mitchelli 

75(70). First metasomal terguni with disc distinctly punctate, punc- 
tures no more than three puncture widths apart at mid-line, 76 
First metasomal tergum with disc impunctate and shiny, or, if 
punctate J punctures weak and sparse and folliclelike ...... 81 

76(75). Femora, tibiae, and tarsi yellow testaceous ( Mesepistenia dis- 
tinctly punctate with shiny interspaces; metasomal terga two 
to five with discs having abundant erect ferrugineous 

pile ) wihnattae 

Femora and tibiae dark or largely so, tarsi occasionally tinged 

with yellow , , , 77 

77(76). Anterior edge of pronotum raised and protruding as an erect 

plate, most evident as an abrupt process above the coxal 
bases; prothoracic tergum very broad with anterior and pos- 
terior edges raised slightly to form a broad , weakly convex 

tergum (Prothoracic spines absent) . . . - , aherrans 

Anterior edge of pronotum flat, tergum narrow and flat 78 

ISilT), Flagellar segments short, about one to one and one-fourth 

times as long as wide; first metasomal tergum with disc 
deeply punctate, punctures no more than two puncture 

* widths apart at mid-line . 79 

Flagellar segments long, at least one and one-half times as long 
as wide; first metasomal tergum with punctures three punc- 
ture widths apart at mid- line, one puncture width apart lat* 
erally (Prothoracic spine long; nervures dark brown), 

77iandibularis 
79(78), Second metasomal tergum with broad basal fascia; first meta- 
somal tergum densely and unifomily punctate, punctures no 

more than one puncture widtli apart . 80 

Second metasomal tergum with no basal fascia; first metasomal 
tergum with disc coarsely punctate, punctures about two 
puncture widths apart; prothoracic spine short and sharp; 

nervures deep brown saritensw 

80(79), Prothoracic spines long and sharp, at least as long as width 

across bases- pile of body tinged with ochreus; North Caro- 
lina .......-.,, howQTdi 

Prothoracic spines very short or absent; pile of body pure 

white; Great Plains sui^tinnae 

81(75), Malar spaces as long as broad; first metasomal tergum impunc- 
tate . albescens 

Malar spaces no more than three-fourths as long as broad; first 
metasomal tergum variable . , 82 



184 The Univebsity Science Bulletin 

82(81), Mesoscutum with punctures mesad from parapsidal lines, shal- 
low and at least two puncture widths apart. rnicheneri 

Mesoscutum with j)unetures mesad from parapsidal lines, no 
more than one puncture width apart ( Mesepistema with 

punctures coarse and dense on upper half) . , 83 

83(82). Wings whitish hyaline with pubescence light. . , . 84 

Wings dusky with abundant dusky pubescence 86 

84(83), Seventh ventral plates roughly quadrangular with apical mar- 
gins broadly rounded, pilose on median and lateral reflexed 
faces; malar spaces three-eighths as long as broad (fig, 50 )j 

laticinctus 
Seventh ventral plates quadrate with apical margins truncate; 
variably pilose; malar spaces one-fom:th as long as broad , . 85 

85(84). Propodcum with basal area sloping sharply ventrally, not pitted 

but having irregular longitudinal rugae; seventh ventral 
plates longer than the width from median to lateral extrem- 
ities, plates quadrate with narrow hyaline nonpilose area 
at the latero-basal margins { fig- 37 ),,,.....,.... . tectwentris 
Propodeum with basal area not sloping sharply ventrally, 
broadly quadrately pitted; seventh ventral plates short, 
slightly broader than long with lateral margins weakly 
rounded and pilose (fig. 36) - ... annae 

S6{83). Rims of nietapleural prominences narrow and testaceous; sev- 
enth ventral phites with discs extended laterally, about 
two and one-half times as broad as long ( fig. 49 ) . . . . soUdaginis 
Uims of nietapleural prominences broad and testaceous; seventh 
ventral plates with discs roughly quadrate, never more than 
one and one-half times as broad as long (fig, 35) 87 

87(86), Mesepisterna coarsely contiguously punctate on upper half; 

pile of body dense, partially coneeahng surface; southern 
coastal areas of Cahfornia ........................ ochraceiis 

Mesepisterna with punctures above, separated by narrow^ 
roughened, shiny interspaces; pile of body sparse, not 
concealing the surface; America east of Continental Di- 
vide . = ^ ^ ^ americanus 

88(2). Face with black pile intermixed along inner orbital margins; 

legs with strong admixture of black or fuscous pile ,...,.. 89 
Face with pile white to tawny grey; legs with pile white to 
pale grey ( except c. consors ) .,.._..,... 92 

89(88). Prothoracic spine long and sharp; mesepistema with pile en- 
tirely black; metasomal terga with no apical fasciae. . calif ornicus 
Prothoracic spine short or vestigial; mesepistema with pile pale 
grey; metasomal terga with white apical fasciae at least 
on first two segments , . , . 90 

90(89)* Legs and discs of metasomal terga three to six with abundant 

erect black pile 91 

Legs and discs of metasomal terga three to six with pile white 
to pale grey . pamscus paniscus 



Revision of the Bee Genus Colletes 185 

91(90). Malar spaces one-half as long as broad; mesoscutum and scutel- 

lum with pile tawny grey, no dark hairs intermixed; seventh 
ventral plates roughly quadrate, densely covered with long, 

laterally directed pile . . , consors pascoensis 

Malar spaces three-fourths as long as broad; mesoscutmn and 
scutellum with pile tawny, intermixed with a few black or 
dark hairs on the disc; seventh ventral plates with apical 
margins broadly rounded, laterobasal margins weakly 
pointed, plates with transverse median bands of pile. (fig. 
62 ) .,,.,__.,_ _ . . , . . pmmcus 

92(88). First metasomal tergum coarsely and densely punctate^ punc- 
tures no more than one puncture width apart; mesoscutum 

coarsely, densely, almost contiguously punctuate 93 

First metasomal tergum with punctures fine or absent, when 
present, punctures at least two puncture widtlis apart^ sur- 
face at times roughened and punctures obscure 102 

93(92), Metapleura weakly protuberant above, protuberance strongly 

rugose; body coarsely and densely punctate; metasomal terga 

with discs having abundant short erect black pile , 94 

Metapleura not protuberant above; body variably punctate, 
punctures not uniformly coarse over entire body; metasomal 
terga with discs having covering of light pile . 98 

94(93). Clypeus shorty strongly convex; flagellar segments one and one- 
third times as long as broad; length 12-14 mm 95 

Clypeus flattened on median suiace; flagellar segments as 
long as broad; length 8-10 mm. ....,,...., 97 

95(94). Seventh ventral plates transverse, apical margins broadly exca- 
vated and fringed with long, light ochreus pile (fig. 27), 

robertsonii 

Seventh ventral plates with apical margins expanded or com- 

■nipv 96 

96(95). Seventh ventral plates with basal portions transverse as in 

robertsonii but with transverse lobes attached to medio- 

apical processes (fig. 30 ) metzi 

Seventh ventral plates with ai^ical margins expanded, tending 
to membranous^ plates roughly quadrate, narrowed laterally 
(fig. 31 ) .,._._ timherhkei 

97(94). Metasomal terga one to three with distinct narrow preapical 

grooves followed by raised flangelike margins; antennal seg- 
ment three one and one-half times as long as fourj malar 

spaces linear ,...-,.... brevicornis 

Metasomal terga one to three with apex smooth, not grooved; 
antennal segment three subequal to four; malar spaces one- 
third as long as broad ... - ,..,...,...... willistoni 

98(93), Malar spaces at least one-half as long as broad^ usually longer; 

mesepisterna coarsely punctate with shiny interspaces , 99 

Malar spaces no more than one-third as long as broad; mesepi- 
sterna finely and shallowly punctate or rugosely punctate 
above ..,,..,..,.. 100 



186 The University Science Bulletin 

99(98). Prothoracic spines long and needlelikej at least twice as long 

as width across the base; malar spaces seven-eighths as 
long as broad , . . ^ texanus 

Prothoracic spines short and sharp, roughly triangular; malar 

spaces one-half as long as broad , . , ...,.,.., wickhami 

100(98), Posterior basitarsi four and one-fourth times as long as broad; 

penis valves lacking dorsal wing (fig. 73); vertex finely and 
%f densely punctate ............... , . . , ..,..,.,, .beamerorum 

Posterior basitarsi three and one-quarter times as long as 
broad; penis valves with broad dorsal wing; vertex im- 

punctate or very sparsely punctate 101 

101(100)* Propodeum with lateral faces shiny, obscurely punctate; basal 

area of propodeum shallowly pitted, sloping sharply basally; 
first mctasomal terguni with median line of disc shiny and 
impimctate; seventh ventral plates long and roughly quad- 
rate with apical end narrowed and having long fringes of 
pile ( fig. 66 ) . . . , sphaeralceae 

Propodeum with lateral faces dull, weakly striate; basal area 
of propodeum with deep quadrate pits not sloping shari>ly 
ventrally; first metasomal tergum without shiny impunctate 
longitudinal mid-line; seventh ventral plates short, semi- 
lunar, with apices broadly rounded ( fig, 65 ) . . nigrifrons 

102(92)* Metasomal terga with apical and basal fasciae absent (Malar 

spaces one-third as long as broad; propodeum with lateral 
and posterior faces dull and weakly roughened ), 

xerophilus cisnjontamis 

Metasomal terga with fasciae broad and grey to white ........ 103 

103(102). Tibiae and tarsi with strong admixture of black and fuscous 

pile; seventh ventral plates square with apical margins 
weakly rounded, long pile over disc except on extreme 
median margins ( fig, 61 ) . , . consors consors 

Tibiae and tarsi with pile white or tawny; seventh ventral 

plates semilunar or elongatcly rectangular 104 

104(103). Metasomal terga three to six with discs having abundant erect 

black or fuscous pile. .......................... ^ , ... . 105 

Metasomal terga three to six with discs having pile white or 

pale grey , , , . 106 

105 ( 104). First metasomal tergum shiny impunctate, or sparsely and finely 

foUiculated; seventh ventral plates small, roughly quadrate 
with apex broadly rounded, discs densely covered with long, 
laterally sloping pile (fig. 61 )...... consors mesocopus 

First metasomal tergum shiny^ distinctly punctate with punc- 
tures one to two puncture widths apart; seventh ventral 
plates diauiond-shaped with median and latt^ral margins re- 
fiexed, sparsely covered with short erect pile (fig. 63) nitescens 
106(104). Mesoscutum and scutellum with admixture of black pile; mes- 

epis tenia very coarsely and densely pimctate; punctures no 
more than one-half puncture width apart above, almost 
contiguous (Seventh ventral plates broad with large mem- 
branous apical expansion (fig. 68) ) .sivenki 



Revision of the Bee Genus Colletes 187 

Mesoscutum and scutellum with pile entirely light; mesepi- 
stema with punctures variable, fine, not contiguous^ sepa- 
rated by shiny interspaces - . . . , 107 

107(106)* Flagellar segments as long as broad j first metasomal tergum 

and mescpisterna with discs distinctly punctate, punctures 

one-half puncture width apart on mesepistema nigrifrons 

Flagellar segments one and one-fourth times as long as broad; 
first metasomal tergum shiny, virtually impunctate except 
for shallow scattered punctures; mesepistema with punc- 
tures about one puncture width apart on discs ...... xerophilus 

108(3), Malar spaces about one and one-eiglith times as long as wide 

or shorter .._... 109 

Malar spaces at least one and one-half times as long as wide, . , 111 

109(108). Antennae with flagclhun light brownish yellow beneath; fla- 
gellar segments less than one and one-half times as long as 
broad (Clypeus closely punctate on basal portion with 
broad, shiny, impunctate areas on either side of mid -line; 
length 6.5-7.5 mm,; seventh ventral plates quadrate with 
apical margins sloping basally towards median edge (fig. 

82 ) ) , . . . _ _ prosopidis 

Antennae with flagelhun dark brownish black or reddish brown 
beneath; flagellar segments more than one and one-half 
times as long as wide 110 

1 10 ( 109 ) , Mesepistema with discs deeply punctate, punctures about one 

puncture width apart; metasomal terga black with reddish 
tinge, second and third metasomal terga with very broad 
apical fascial dei^ressions; seventh ventral plates broadened 
apically and abruptly truncate with inner apical margins 
strongly reflexed (fig. 76); malar spaces broad, slightly 
longer than broad; clypeus long with broad, shiny, im- 
punctate areas on either side of the mid-hue ......... algarobme 

Mesepistema with discs having punctures two puncture widths 
apart; seventh ventral plates broadened and rounded api- 
cally ( fig. 83 ) ■ malar spaces narrow, slightly shorter than 
broad; clypeus short and closely punctate across base, shiny 
areas on either side of mid-fine with coarse, scattered punc- 

11 1( 108). Seventh ventral plates with apical margins convex 112 

Seventh ventral plates with apical margins truncate or slightly 

concave (Far western and southwestern) 113 

112(111). Mesepistema with disc deeply punctate, punctures less than 

one puncture width apart; nervures of hind wing lights 
almost yellowish; seventh ventral plates shorter^ apices more 
strongly convex (fig. 81); western part of Great Plains, 

petalostemonis 
Mesepistema with disc more finely punctate, punctures more 
than one puncture width apart; nervures of hind wing 
brown; seventh ventral plates longer, apices less strongly 
convex (fig* 79); southwestern deserts. ........... salicicola 



188 The University Science Bulletin 

113( 111). Malar spaces at least twice as long as broad; flagellar segments 

strongly tinged with yellow beneath; tarai black (Flagellar 
segments about twice as long as wide; clypeus with deep 
median sulcus, densely and finely punctate; seventh ventral 
plates much as in algarobiae, slightly expanded apically and 
broadly rounded with long lateral and median fringes of 

hair (fig. 77); length 8.5-9,5 mm.) chjpeonitens 

Malar spaces approximately one and one-half times as long as 
broad; flagellar segments strongly tinged with ferrugineous 
beneath; tarsi variable 114 

114(113)* Flagellar segments approximately one and three-fourths times 

to twice as long as broad; metasomal terga black tinged 
with testaceous at apical fascial depressions; length S-9 mm., 115 
Flagellar segments approximately one and three-eighths times 
as long as broad; metasomal terga strongly tinged with blue 
to give discs bluish black lustre; length 7 mm. (Seventh 
ventral plates short with lateral fringes of pile as well as a 
long clump of pile arising at upper lateral face immediately 
beneath articulatory condyle (fig. 80) ) daleae 

115(114). Seventh ventral plates long, expanded and slightly rounded 

at apex, about twice as long as wide (fig. 79); second 
metasomal tergum with disc deeply punctate, punctures 

about two puncture widths apart; length 8 mm. salicicola 

Seventh ventral plates slightly expanded apically, apex trim- 
cate, about one and one-fourth times as long as wide (fig. 
78 ) ; second metasomal tergum with disc smooth^ shiny, and 
impunctate; length 8 mm. ....................... covilleae 

KEY TO THE FEMALES 

As in the males, further material is submitted to facilitate the 
separation of couplets 1, 2, and 3. Parallelisms in one or another 
of the key characters are exhibited by many species that are not 
members of the groups in question. The ensuing remarks are 
therefore provided* 

Forms which should go to couplet 57 {americaniis group) ex- 
hibit the following characters: malar spaces no more than one-half 
as long as broad; clypeus densely punctate, punctures striate to 
ovate; prothoracic spines short and sharp; flagellar segments about 
three-fourths as long as broad; propodeum with lateroposterior 
margins abrupt or ridged, not rounded; pile of body usually white 
to dusky to tinged with ochreus. 

Forms which should go to couplet 76 ( consors group ) exhibit the 
following characters; malar spaces no longer than one-half as long 
as broad; clypeus variably punctate, punctures ovate to striate; 
flagellar segments short, about one-half as long as broad, sometimes 
slightly longer; propodeum with basal area narrow and sloping 



Revision of the Bee Genus Colletes 189 

sharply ventrally, lateral and posterior faces finely striate and rough- 
ened, Iateroi:>osterior margins rounded; pile of body long and dusky^ 
often intermixed with black on head and thorax. 

Forms which should go to couplet 95 {daleae group) exhibit the 
following characters: malar spaces no longer than three-fourths as 
long as broad; clypeus usually elongate with longitudinal median 
sulcus bordered by lateral, shiny, sparsely punctate rims; median 
sulcus densely punctate, rims sparsely punctate with round punc- 
tures; flagellar segments at least three-fourths as long as broad, 
usually much longer; propodeum with basal area smooth and broad, 
usually not sharply pitted but with a few weak longitudinal rugae, 
lateral and posterior faces shiny with numerous fine punctures, 
lateroposterior margins rounded; pile of body long and white; 
species small, less than 10 mm., and found only in western parts 
of the Great Plains and Lower Austral zone, 

1, Metapleura each with dorsal prommence or horizontal carina 

usually with testaceous rim; malar spaces no longer than 
one-half as long as broad; last exposed sternum with apex 
not depressed , , . 57 

Metapleura with no dorsal prominence, or, if weak pronii- 
nence^ with carina curving ventrally well in front of pos- 
terior margins; if having nietapleural prominence then malar 

spaces as long as broad _........_. 2 

2(1). Median flagellar segments short, usually one-half to three- 
fourths as long as broad when viewed from above j and 
last exposed sternum with apical portion strongly depressed 
with basal arcuate band of overhanging pile; when apical 
depression very small, sterna with strong scopa 76 

Median flagellar segments usually as long as broad when viewed 
from above; last exposed sternum usually lacking depressed 

apical portion . . . 3 

3(2). Clypcal punctures sparse and round, and clypeus with longi- 
tudinal median sulcus ( sulcus not evident in some specimens 
of algarobiae); propodeum wiUi basal area broad and not 
distinctly quadrately pitted .,,.,.,,., 95 

Clypeal punctures elongate, at least apically, or, if notj clypeus 
lacking median sulcus; propodeum with basal area usually 

deeply pitted 4 

4(3)* Mesoscutuni and/or scutellum with admixture of black pile. . . S 

Mesoscutum and scutellum with no black pile ............... 34 

5(4). Malar spaces at least three-fourths as long as broad , . , 6 

Malar spaces usually one- half as long as broad or less 10 

6(5), Malar spaces one and three-eighths times as long as broad 

(Metasomal tergum one coarsely punctate; mesepistema 
dull, finely roughened; length 11-13 mm.) ..,,,, , . .validus 

Malar spaces no longer than broad __,.,_,, 7 



190 The University Science Bulletin 

7{6). First metasomal tergum coarsely and densely punctate, punc- 
tures no more than one puncture width apart (Propodeum 

with basal area very narrow, obscurely pitted) . ^ skinneri 

First metasomal tergmii shiny, impunctate or sparsely follicu- 

lated . . , 8 

8(7)* Prothorax with dorsal lateral margins rounded, not spined; 

propodeum with dorsal and posterior faces dull and rough- 
ened, lateroposterior margins rounded . . . .impunctatus lacusfris 
Prothorax with short, sharp spines; propodeum with dorsal and 
posterior faces shiny and weakly pitted, lateroposterior mar- 
gins angulate^ separated by weak, elevated carinae 9 

9(8). Vertex with pile all light, occasionally a few dark hairs inter- 
mixed; metapleura with weak prominences above, prom- 
inences with narrow testaceous rims; tegulae light brown, 

Ion gi fades 
Vertex with numerous dark hairs intermixed; metapleura 
weakly protuberant above but without testaceous rims; 

tegulae dark brown to black . , productus 

10(5), First metasomal tergum very finely punctate, punctures follicle- 
like and at least two puncture widths apart on discal area. . 11 
First metasomal tergmn deeply punctate, punctures one to one 
and one-half puncture widtlis apart laterally, or punctures 

fine and contiguous , . . . 21 

11(10)* Last metasomal sternum with elevated carinae curved niesad 

apically; first metasomal tergum with apical margin abrupt 
and rounded, fascia arising as apical fringe (Prothoracic 

spines short and sharp ) ,,.....,,., arizonensis 

Last metasomal sternum unifonn; first metasomal tergum with 

apex flattened and fascial hairs arising subapieally 12 

12(11), Prothoracic spines short and obliquely truncate \\ath anterior 

margins extending beyond posterior (Malar spaces one-fifth 

as long as broad) rufocincfiis 

Prothoracic spines pointed, not truncate 13 

13(12), Mesoscutum and scutelliun with pile long, dense, and erect, 

sparsely intermixed with dark hairs; mesepistema with shiny 
interspaces above; procoxal spines short, about as long as 

broad . ht/aUnus 

Mesoscutmii and scutellmn with light pile restricted to peri- 
pheral portions, abundant black pile intermixed over discal 
areas; mesepistema closely or contiguously punctate and 

roughened; procoxal spines variable. 14 

14 ( L3). Second metasomal tergum with basal fascia. 15 

Second metasomal tergum without basal fascia ............ 17 

15(14), Proco.xal spines absent; propodeum with basal area longitudi- 
nally striate, not quadrately pitted perUeucus 

Procoxal spines at least as long as wide; propodeum with basal 

area deeply quadrately pitted . . . , . 16 

16(15). Wings whitish hyaline; vertex with pile all Hght; second meta- 
somal tergum shiny, almost impunctatej laterally except for 
few foUicles; clypeus striately punctate with broad shiny 



Revision of the Bee Genus Colletes 191 

interspaces becoming larger basally; niesepistema coarsely 
and rugose ly punctate above with no interspaces evident . , louisae 

Wings dusky hyaline; vertex with weak admixture of black 
pile; second metasomal tergum shiny, finely punctate with 
punctures about one and one-half puncture widths apart; 
clypeus closely, striately punctate to apex; mesepistema 
densely and rugosely punctate but with evident interspaces 

on anterior faces = , fulgidus 

17(14). Malar spaces one-half as long as broad; mesepistema coarsely, 

contiguously punctate (Length 11-13 mm.) caroUnus 

Malar spaces no more than one-third as long as broad; mesepi- 
stema coarsely punctate with shiny interspaces . - . 18 

18(17). Metasomal sterna coarsely and sparsely punctate, punctures at 

least two puncture widths apart^ sterna with sparse, short, 
erect pile and broadly interrupted apical fasciae . . . . , perileucus 

Metasomal sterna dull, finely punctate, sterna lacking apical 

fasciae ........__ _ 19 

19(18), Clypeus short, strongly convex, densely punctate to apex- 
sterna with dense scopa; compound eyes very large and 
broad; malar spaces linear .......,_. titusensis 

Clypeus long, flattened or sulcate medially, sparsely punctate 
with shiny interspaces; malar spaces one-fourth to one-third 

as long as broad .,,.,,....,...-....,.,,_ 20 

20(19), Clypeus with deep longitudinal median sulcus^ extending from 

base to apex; prothoracic spines very short and sharp; malar 
spaces one-third as long as broad ....,_......... intermixtus 

Clypeus not sulcate medially, but flattened; prothoracic spines 
at least as long as width across base; malar spaces one- 
fourth as long as broad _ _ chamaesarachae 

21(10). Last metasomal sternum with raised lateral longitudinal ridges 

extending to apex . , 22 

Last metasomal sternum simple, undiflFerentiated 23 

22(21), Prothoracic spines short and sharp; second metasomal tergum 

abriiptly depressed basally; lateral ridges of last sternum 
weak and arcuate . _ arizonenMs 

Prothoracic spines vestigial; second metasomal tergum not de- 
pressed basally; lateral ridges of last sternum strong and 

straight . . . , compactus 

23(21). Posterior basitarsi twice as long as broad (Clypeus flattened, 

obscurely striately i^unctate; malar spaces one-third as long 
as broad) .,,,,, latitarsis 

Posterior basitarsi at least three times as long as broad, usually 

longer 24 

24(23), Prothoracic spines long and sharp, longer than width across 

base of spine , , 25 

Prothoracic spines short, absent or obliquely truncate, never 

terminating in a needlelike point to edge of head . . , 29 

25(24). Fore coxae with long spines, at least as long as broad 26 

Fore coxae lacking spines 27 



192 The University Science Bulletin 

26{25). Scutelluiii striately punctate; prothoracic spines long and sharp, 

protruding to sides of head; first metasomal tergum closely 
punctate, punctures approximately one puncture width 

apart - - simtilam 

Scutelluni coarsely punctate, punctures nut at all striate; pro- 
thoracic spines sharp, not protruding to sides of head; first 
metasomal tergum with punctures sparse and weak . , . . fulgidus 
27(25), Clypeus long, flat, dull, and roughened; flagellar segments 

short, about five-eighths as long as broad . willistoni 

Clypeus short, convex, coarsely punctate with shiny inter- 
spaces; flagellar segments about as long as broad 28 

28{27), Malar spaces linear; propodeum strongly ridged on upper pos- 
terior face outside of triangle; apical fasciae narrow and 

weak, often absent medially nudus 

Malar spaces one-third as long as broad; propodeum with pos- 
terior face dull and roughened outside of triangle; apical 

fasciae broad, dense, and w^iite. giknsis 

29{24). Procoxal spines long, at least three times as long as broad. , _ 30 

Procoxal spines vestigial or absent 31 

30(29), Prothoracic spines obhquely truncate, with posterior margins 

extending beyond anterior; first metasomal tergum with 

abundant long erect ochreus pile angelicu.^ 

Prothoracic spines short, blunt to tnmcate with anterior mar- 
gins extending beyond posterior; first metasomal tergum 
with little discal pile except for short lateral fringes rufocinctus 
31(29). Antennae very short, flagellar segments one-half as long as 

broad; length 9-10 mm, 32 

Antennae long, flagellar segments as long as broad; length 12- 

14 mm, 33 

32(31). Metasomal terga one to three with distinct narrow preapical 

groove, followed by raised flangelike margins; clypeus closely 

punctate ^ ■ brevicomis 

Metasomal terga one to three with apical margins entire and 
smooth, broadly fasciate; clypeus flat, dull, and weakly 

roughened _._,... ._,..... willistoni 

33(31). Mesepistema dull, roughened, obscurely punctate; first meta- 
somal tergum with punctures close and dense, no more than 
one puncture width apart; metasomal fasciae weak and 

tinged with ochreus - * ■ ■ ■ inaequalis 

Mesepisterna shiny, deeply and coarsely punctate with punc- 
tures about one-half puncture width apart; first metasomal 
tergum finely punctate with punctures about one puncture 
width apart; metasomal terga tinged with metallic blue; 

metasomal fasciae broad, dense, and white cercidii 

34(4). Prothoracic spines sharp, at least as long as width across base , 35 

Prothoracic spines short or absent, never as long as width 

across base ^ 47 

35(34). First metasomal tergum shiny with few scattered fine punc- 
tures; terga never covered or partially obscured with ap- 
pressed pubescence . * , - 36 



% W f 



Revision of the Bee Genus Colletes 193 

First nietasomal terguni distinctly punctiite, punctures about 
one and one-half puncture widths apart; terga often cov- 
ered or partially obscured by apprcssed pubescence 39 

■36(35), Last metasomal sternum with weak, elevated lateral longi- 
tudinal carinae curved medially at apex; tegulae black, 

distinctus 

Last metasomal sternum lacking carinae. 37 

37(36). Second metasomal tergum uniform, with very narrow, incon- 

spiciious white basal fascia, most evident laterally; first 
metasomal tergum with a few weak folliclclike punctures, 

htjalinus 
Second metasomal tergum weakly depressed basally with broad 
basal fascia; first metasomal tergum variably punctate, punc- 
tures usually coarse .,...._ . . _ 38 

38(37). First metasomal tergum with apical fascial margin not de- 
pressed medially; metasomal terga five and six with pile of 
discs light ochreus to golden; first metasomal tergum shiny, 

a few coarse punctures scattered over surface birhnamii 

First metcisomal tergum with apical fascial margin abruptly de- 
pressed throughout its breadth; metasomal terga five and 
six with pile of discs deep fuscous to black; first metasomal 
tergum with punctures concentrated on median discal area, 

slevini 
39(35). Malar spaces linear; body very coarsely, contiguously punctate; 

metasomal terga one and two with punctures as coarse as 

those on mesoscutum . . _ . robeHsonii 

and timberlakei 
Malar spaces one-third as long as broad; body variably punc- 
tate; metasomal terga one and two with punctures much 

finer than tliose of mesoscutum _ 40 

40(39). Metasomal tergum three without basal fascia; metasomal terga 

four and five with discs having deep fuscous to black pile; 
sou tell um coarsely punctate over posterior three-fourths, 

weakly striate on anterior half. ..........,_ , . 41 

Metasomal tergum three with basal fascia; metasomal terga 
four and five with discs having tawny to ochreus pile; 

scutellum shiny, sparsely punctate 46 

41(40), Second metasomal tergum with deep basal depression and 

weak white fascia, depression deepest medially; malar 

spaces about one-half as long as broad 42 

Second metasomal tergum shallowly or not depressed basally 
witli weak white fascia; malar spaces less than one-half as 

long as broad _ . 43 

42{41), First metasomal tergum with apex abruptly depressed, disc 

shiny, finely and sparsely punctate with punctures two to 

four puncture widths apart _ slevini 

First metasomal tergum not strongly depressed apically, disc 
densely and coarsely punctate to apex, with punctures one 
puncture width apart wootoni 

7_1542 



194 The Univebsity Science Bitlletin 

43(41), Scutellum with anterior half weakly, longitudinally striate or 

punctate to edge; first metasomal terguni finely punctate 
with punctures one to tw^o puncture widths apart, 

hyalinus gaudialis 
Scutellum with anterior one-third nonpunctate, nonstriate; first 
metasomal tergum with punctures uniformly dense, no more 

than one puncture width apart . . . . , ..,.,..,,... 44 

44(43). Length 8-9 mm. ^ metasomal terga one and two punctate with 

interspaces dull; montane species from southern Cahfornia, 

lutzi pinorum 
Length 10-12 mm.; metasomal terga one and two punctate with 

45(44), Sternal discs rather dull, with a few fine punctures; mesepi- 

sterna with punctures separated^ about one puncture width 

apart; northern and western species . , kincaidii 

Sternal discs sluny and usually coarsely punctate, punctures 
about one and one-half puncture widths apart; mesepistema 
with punctures closer and almost contiguous on upper 
half; southern half of United States eulophi 

46(40). Length 9 mm.; elypeus with sparse, coarse longitudinal punc- 
tures to apex; second metasomal tergum densely punctate 
with punctures about as coarse as those of tergum one; 

antennal segments about as long as broad phaceliae 

Length 7 mm.; elypeus with apical one-half shiny impunctate 
laterally; second metasomal tergum finely folliculated, dull; 
antennal segments two-tliirds as long as broad lutzi 

47(34), Eyes with inner orbital margins nearly parallel; mesepistema 

dull, shallowly, obscurely punctate 48 

Eyes with inner orbital margins strongly convergent below; 
mesepistema shiny to variable , . . . 49 

48(47), Posterior basitarsi three and one-half times as long as broad; 

mesoscutum with pile ochreus; lengtli 13 mm.; western part 

of Great Plains andrewsi 

Posterior basitarsi four and one-fouri:h times as long as broad; 
mesoscutum with pile tawny; length 11 mm*; eastern sea- 
board aestivalis 

49(48). Mctapleura strongly protuberant above, protuberances with 

narrow black rims; malar spaces as long as broad . . , . productus 
Metapleura not protuberant above; malar spaces less than 
three-fourths as long as broad, , . , . 50 

50(49}, Mesepistema dull^ obscurely or finely and densely punctate; 

mesoscutum with pile bright ochreus ................ 51 

Mesepistema rugosely punctate with shiny, although sometimes 
roughened, interspaces; pile variable in color 52 

51(50), First metasomal tergum finely and densely punctate, punctures 

one-half puncture width apart; tergal fasciae complete and 

white; length 11 mm . ciliatus 

First metasomal tergum shiny impunctate to sparsely foUicu- 
lated; tergal fasciae absent or evident only as lateral fringes; 
length 14-15 mm, , . , thoracicus 



Revision of the Bee Genus Colletes 195 

52(50), Apical metasomal sternum with posterior half shaq^ly de- 
pressed, apex hyaline nonplumose with long pile overhang- 
ing depressed area , 53 

Apical metasomal sternum simplcj not longitudinally differ- 
entiated or with weak lateral longitudinal ridges . 54 

53(52), Malar spaces linear; metasomal terga two and three with no 

evident basal fasciae; nervures and stigma dark brown to 

black turgiventris 

Malar spaces half as long as broad; metasomal terga two and 
three with weak basal fasciae; nervures and stigma brown, 

larTeae 
54(52). First metasomal tergum coarsely and densely punctate, punc- 
tures no more than one puncture width apart 55 

First metasomal tergum shinyj sparsely punctate or finely fol- 

55(54), Metasomal tergum two deeply depressed basally throughout; 

malar spaces one-half as long as broad; posterior tibiae with 

pile light . ...,.,... wootoni 

Metasomal tergum two shallow^ly depressed basally, depression 
not evident medially; malar spaces one-third as long as 
broad; posterior tibiae with admixture of black pile , , . hryanti 

56(54). Last metasomal sternum with weak, elevated lateral longitudi- 
nal carinae curved medially at apex; second metasomal ter- 
gum finely and densely folliculated; tegulae black. . . .distinctus 
Last metasomal sternum lacking carinae; second metasomal 
tergum sparsely folliculated; tegulae brown hyaline. . . .brimleyi 

57(1). Mesoscutum covered with short, dense, plumose pubescence 

giving the surface a niosslike mat appearance. 58 

Mesoscutum covered with moderately long pile, not dense and 
crowded to conceal surface , _ . _ 60 

58(57). Anterior edge of pronotum raised and protruding as an erect 

platCj most evident as an abruptly protruding plate above 
the coxal bases; pronotum very broad; metapleural promi- 
nence with broad testaceous rim ....,._. aberrans 

Anterior edge of pronotum not protruding as an erect plate 
above the coxal bases; metapleural prominence with narrow 
testaceous or dark brown rim 59 

59(58)< Metasomal terga one to five covered with short, dense, ap- 

pressed pubescence concealing the surface; legs yellow to 
Light brown-yellow apically from trochanters; western part 

of Great Plains ,__... _ _ wilmaUae 

Metasomal terga one to five not completely covered with ap- 
pressed pubescence, a narrow prefascial area on each disc 
free from pile; legs reddish brown, tending to darker brovra 
basally; metapleural prominence weakly protuberant with 
a narrow dark brown rim; known only from North Carolina^ 

howardi 
60(57), Wings whitish hyaUne, bare or covered with short white pu- 
bescence , 61 

Wings dusky hyaline, covered with short, deep ochreus to 
dusky pubescence _ . _ _ 64 



196 TiiE University Science Bulletin 

61(60). First metasomal tergum with disc finely and closely punctate, 

punctures shallow and about one puncture width apart on 
lateral faces; metasomal terga with short , sparse, ai^pressed 
pubescence over surface . . . . , . ,, . . . . .......,._.. susmmae 

First metasomal tergum shiny impunctate or finely follic- 
ulated laterally with follicles at least two folHele widths 
apart; metasomal terga with at most the basal half covered 
with oppressed pubescence ...,,.. 62 

62(ei)p Malar spaces one-half as long as wide; mesepisterna and 

mesoscutuni with discs deeply and coarsely punctate, punc- 
tures no more than one puncture width apart , albescens 

Malar spaces one-fourth as long as wide or less; mesepisterna 
and mesoscutum with discs obscurely punctate 63 

63(62), Metasomal tcr^^a one to four covered with short, dense^ ap- 

pressed pubescence, completely concealing the surface j 

tectlventris 
Metasomal terga one to four with discs bare except for basal 
fascia of second metasomal tergum , . , micheneri 

64(60). Metasomal terga one to four covered with short, appressed 

pubescence completely concealing the surface. . . . , . , 65 
Metasomal terga with discs bare^ or partially covered w_th 
semierect pile not concealing the surface . 67 

65(64), Mesepisterna shiny and distinctly punctate, punctures at least 

one puncture width apart; mesoscutum sparsely, shallowly 
punctate; metasomal terga with pubescence sparse but com- 
plete and appressed (Pile of head and thorax yellow), 

solidaginis 
Mesepisterna dull, coarsely punctate with punctures almost 
contiguous; mesoscutum with punctures coarse^ about one 
puncture width apart; metasomal terga with pubescence 
dense over entire surface 66 

66(65). Pile of head and thorax ochreus; wings dusky hyaline with 

abundant ochreus pubescence over surface; metapleural 
prominence with rim variable but usually narrow and tes- 
taceous; length 9-10 mm. , ochraceus 

Pile of head and thorax pale ochreus to dusky grey; wings with 
sparse, light ochreus pubescence; nervures light yellow- 
brown; metapleural prominence with rim narrow^ black to 
deep brown; length 8-9 mm tectiventm 

67(64). Metapleural prominence strongly protuberant with a broad 

rim, abruptly declivous beneath . . , 68 

Metapleural prominence weakly protuberant with narrow 
brown to black rim, shallowly concave beneath. . . , , , , . , . 71 

68(67). Tcgulae black; fascial foveas with upper margins curved 

strongly mesad^ extending two- thirds of the way to lateral 
ocelli from eyes; mesoscutum with pile dusky grey. . . saritensis 
Tegulae brownish hyaline ; fascial foveae with upper margins 
rounded (not curved) mesad^ extending less than half way 
to lateral ocelli from eyes; mesoscutum with pile tinged 
with ochreus 69 



Revision of the Bee Genus Colletes 197 

69(68). Second nietasomal terguni witli broadj dense basal fascia, at 

least as broad as nonpubesccnt area between basa! and 
apical fasciae; first metasomal terguni finely and densely 
punctate especially laterally; metasomal terga three to five 
with short, white, semierect pile, giving the surface a 
whitish sheen; apical fasciae broad and w^hite; lateral fringes 
of first metasomal tergum dense and continuous to apical 
fascia; mesoscutum with pile white to ochreus . mandibuhms 
Second metasomal terguni with basal fascia weak or absent, 
not more than one-third as wide as nonpubesccnt area be- 
tween basal and apical fasciae; first metasomal tergum with 
disc sparsely foil ieu la ted and shiny; metasomal terga three 
to fi\^e bare and shiny, occasionally with a few semierect 
hairs; apical fasciae weak and narrow; first metasomal ter- 
gum with lateral fringes weak and usually not continuous to 
apical fascia; mesoscutum with pile deep ochreus to yellow, 70 

70{69). Second metasomal terguni with no basal fascia; mesepistema 

coarsely and shallowly punctate with shiny interspaces; 
propodeum with posterior face traversed by numerous 

rugae; pile of body sparse, pale grey . . , bmdleyi 

Second metasomal tcrgmii with a narrow basal fascia; mesepi- 
stema densely, almost contiguously, punctate; propodeum 
with posterior face smooth^ sparsely punctate; i)ile of body 
tinged with fuscous . , ..,.,... .... americanus 

71 (67), Mesoscutum and scutellum with strong admixture of black and 

dark hairs; second metasomal tergum with no basal fascia; 

mesepistema rugose ,.,... thtjsanellae 

Mesoscutum and scutellum with pile entirely light; second 
metasomal tergum with strong basal fascia; mesepistema 
distinctly punctate ............ ^ . . 72 

72(71). Anterior coxae with spines rudimentary; posterior basitarsi 

about three and one-fourth times as long as broad, laticinctus 
Anterior coxae with spines well developed; posterior basitarsi 
four to five times as long as broad 73 

73(72). Posterior basitarsi five and one- fourth times as long as 

broad; mesepistema densely and contiguously punctate, 
with a dense covering of long, fine^ tawny to white pile; 

length 12 mm . , gtjpsicolens 

Posterior basitarsi four times as long as broad; mesepistema 
with punctures separated by shiny interspaces below; pile 
short and not obscuring surface, usually tinged with yellow, 74 

74(73). Second and third metasomal terga with distinct basal fasciae; 

wings witli nervures light yellow-brown; antennae tinged 

with yellow . .' , , annae annae 

Second nietasomal tergum with weak basal fascia ^ fascia absent 
on third; wings with nerv^ures deep brown; antennae dark 
brown .,,,_.. 75 

75(74). Mesepistema with upper half finely, densely ^ contiguously 

punctate, almost roughened; mesoscutum and scutellum 
with pile tinged with deep ochreus; America east of Con- 
tinental Divide mitchelU 



198 The University Science Bulletin 

Mesepisterna sTiarply punctate, punctures separated by broad 
shiny interspaces; mesoscutum and scutellum with pile 
tawny to tinged with yellow; southern California and ex- 
treme southwestern United States , , .... annae dissepfiL^ 

76(2). Inner orbital margins^ mesepisterna^ and upper genal areas 

with pile black or with admixture of black pile ........ . 77 

Inner orbital margins^ mesepistema, and upper genal areas 

with pile white or pale grey ... . . ^ 85 

77(76). Pile of mesepisterna black, 80 

Pile of mesepisterna, especially upper half, white to tawny grey 
( Face with abundant white pile about antennal bases ) . . 78 

78(77). Metasomal terga with apical fasciae absent; vertex with pile 

light to dusky; southern California xerophilus cismonfanus 

Metasomal terga with apical fasciae present; vertex with pile 

variable ,....., 79 

79(78), Mesoscutum and scuteEum with pile all light; pile of face, 

vertex, and genal areas predominantly black, paniscus paniscus 
Mesoscutum and scutellum with admixture of black or dark 
pile; pile of face, vertex, and genal areas predominantly 

white ,..,,.......,...,. . .xerophilus xerophilus 

80(77). Prothoracic spine long and distinct, at least one and one-half 

times as long as width across the base (Pile of head, 
thoracic pleura, and legs black; metasomal fasciae ab- 
sent ) , , . calif oniicus 

Prothoracic spine absent or vestigial , , , . , . 81 

81(80). Mesoscutum and scutellum with strong covering of pale grey 

to light ochreus pile . 82 

Mesoscutum and scutellum with admixture of black pile 83 

82(81), Metasomal terga two to five with apical fasciae very weak but 

discernible at lateral margins; mesoscutum and scutellum 
with pile white to pale grey; propodeum with pile white, 

consors censors 
Metasomal terga two to five with no apical fasciae; mesoscutum 
and scutellum with pile light ochreus; propodeum with 

strong admixture of black pile conusors pascoensis 

83(81). Metasomal terga one to five with dense white apical fasciae at 

least laterally; malar spaces one- third as long as wide; 
metasomal terga one and two finely punctate, punctures one 

to two puncture widths apart, nigrifrons 

Metasomal terga one to five \\ith fasciae absent, at times evi- 
dent laterally on tergum one; malar spaces one-half as long 
as wide; metasomal terga one and two sparsely follicu- 
lated 84 

84(83). Metanotum and mesoscutum with strong admixture of black 

pile medially . . , panisctis mcrfensiae 

Metanotum and mesoscutum with few scattered black hairs, 

paniscus scuHeni 
85(76). First metasomal tergum densely punctate or foIUculated with 

punctures one to two puncture widths apart 86 

First metasomal tergum impunctate or finely and sparsely foI- 
Uculated 89 



Revision of the Bee Genus Colletes 199 

86(85). Metasomal terga one and two with distinct narrow preapical 

grooves followed by raised flangelike margins (Metasomal 

terga coarsely and densely punctate) brevicornis 

Metasomal terga one and two with apical margins smooth 87 

87(86). Clypeus long, flattened medially with a very faint longitudinal 

median sulcus; prothoracic spines long, needlelike, about 
one and one -half times as long as width across the base, 

texantis texanus 
Clypeus short J iinifonnly convex, shiny; prothoracic spines 

short, triangular 88 

88(87). Large robust species, 14 mm,; metasomal terga one to three 

coarsely and densely punctate, apical fasciae in sharply 
declivous, nonpunctate depressions . . . Tohertsonii and timberlakei 
Smaller species^ 7-8 mm.; metasomal tergum one more densely 
punctate than bA^o or three, apical fasciae not in marked 

depressions • . linsletji 

89(85). Last metasomal sternum with the apical one fourth or less de- 
pressed; body with pile short and white with few black hairs 
intermixed; fascial f oveae strongly depressed above ,.,.,.. 90 
Last metasomal sternum with apical one half strongly de- 
pressed; body with pile long^ sparse^ and dusky; fascial 

foveae weakly depressed above 92 

90(89). Mesoscutum and scutellum with discs having strong admLxture 

of black pile, at least one half of pile black swenki 

Mesoscutum and scutellum with pile light, a few dusky hairs 
intermixed (Clypeus shorty convex, shiny, very sparsely, 

coarsely punctate ) . 91 

91(90). Fascial foveae broad above, extending over half way from eyes 

to lateral ocelli; some short black pile over mesoscutum, 

scopivenfer 
Fascial foveae naiTOW above^ extending about one third of way 

from eyes to lateral ocelli* black pile restricted to few hairs 

on scutellum aridus 

92(89), Metapleura with a few dark hairs on upper faces; head very 

broad, about one and one-third times as broad as long 
{ Metasomal terga two and three finely and densely pmic- 
tate or coarsely folliculated with shiny interspaces; Cali- 
fornia ) , . , _ , nitescens 

Metapleura wath pile white; head about one and one-fifth times 
as broad as long or less 9S 

93(92). Clypeus coarsely, conti^iously, striately punctate to apex; mes- 

episterna coarsely and densely pimctate above, punctures 
one-half puncture width apart; fascial foveae obscure, me- 
dian margins not discernible, dorsal margins extending 
barely above upper inner orbital margins; tegulae black; 

California , . , sphaeralceae 

Clypeus irregularly punctate with shallow^ obscure punctures, 
weakly rugose and shiny; mesepistema shallowly punctate 
with shiny interspaces; fascial foveae variable 94 



200 The University Science Bulletin 

94(93). Fascial foveae very broad and deep,' dorsal edge extending at 

least two thirds of the way to the lateral ocelli j metasomal 
tcrga two and three shiny, impimctate; tegulae brownish 
hyahne; America east of Continental Divide consors mesocopus 

Fascial foveae obscure, narrow, not extending above upper 
inner orbital margins; metasomal terga two and three finely 
follieulated and shiny; tegulae deep brown to black; mon- 
tane species, Rocky Mountains panisciis panlscus 

95(3). Metasomal terga nearly or completely covered with shorty ap- 

pressed pubescence, most nearly complete on metasomal 
terga three to five . . , 96 

Metasomal terga having discs nonpubescent, except for basal 

fasciae sometimes present on terga two and three 98 

96(95). Malar spaces long, at least as long as broad; posterior basitarsi 

four times as long as broad . 97 

Malar spaces three-fqiirths as long as broad; posterior basitarsi 
broad, three and one-fourth times as long as broad (Pile of 
vertex, mesoscutum, seutellum and apical metasomal terga 

strongly tinged with ochreus) comlleae 

97(96). Pile of vertex and mesoscutum long and deep ochreus; mesepi- 

sterna dull above with punctures shallow and obscure; 
prothoracic spines absent; nervures deep brown to black; 
length 10-11 mm. , . . . cbjpeonitens 

Pile of vertex and mesoscutum short and pure white; mesepi- 
stema shiny with deep punctures separated by shiny 
interspaces; prothoracic spines short and sharp; nervures 
Hght yellow-brown, especially basally; length 8-9 mm,, 

petalostemonis 
98(95)* Mesepisterna with punctures shallow and sparsely scattered 

over sliiny black surtace, punctures two to four puncture 
widths apart on disc; malar spaces one-half as long as broad 
or less , , , . , ,.......,,.._.... 99 

Mesepisterna with punctures deexD and close, no more than one 
puncture width apart on disc; malar spaces three-fourths to 
seven-eighths as long as broad (shorter in deserticola 

X im ij i J FTr»«<i>«»«t.ii x'j^^' 

99(98). Antennae with under surface of flagelium light brownish yel- 
low; mesepisterna with punctures almost obscure, at least 
four puncture widths apart on discs; metasomal teiga five 
and six with disc having abundant golden erect pile; length 
8 mm. ...,__... , . . . . prosopidis 

Antennae witli under surface of flagelium reddish brown; mes- 
episteraa with punctures distinct but at least two puncture 
widths apart on disc; metasomal terga five and six with 
disc having abundant^ deep ferrugineous to blacky erect 

pile; length 9-9.3 mm. algarobiae 

100(98). Metasomal terga six (and sometimes five) with disc having 

abundant, deep ferrugineous to black hairs; prothoracic 
spines at least as long as broad at base 101 



Revision of the Bee Genus Colletes 201 

Xh'tasonial terga five and six having disc covered with light 

hairs; prothoracic spines vestigial or absent saUcicola 

101 { 100). Malar spaces about seven-eighths as long as broad; metasomal 

terga two and three witli weak basal fasciae; apical fasciae 

loose and broad; length 8,5-9 mm, . daleae 

Malar spaces sHghtly less than three-fourths as long as broad; 
metasomal terga tw^o and tliree with broad, dense basal 
fasciae; apical fasciae dense and broad; length 9.5-10 mm., 

deserticola 

DESCRIPTIONS OF THE SPECIES 

Group I — product us 

Colletes productus Robertson 

■ (Fig. 1} 

Colletes productus Robertson, 1891, Trans. Amer. Ent. Soe.^ voL 18, p. 62; 
1904, Canadian Ent., vol. 36^ p. 278; Swenkj 1908, Univ. Nebraska Studies, 
voL 8j p. 38; Leonard, 1926, Cornell Agric. Exper. Sta. Mem. no. 101, p. 
1021; Robertson, 1928, Flowers and Insects, p. 10; Graenicher, 1935, Ann, 
Ent. Soc, Amer., vol. 28, p. 301 (questionable); Brimley, 1938, Insects 
North Carohna, p. 451. 

Although this species resembles the americanus group, a multi- 
tude of characters clearly indicate that it does not belong there, 
and both sexes are easily distinguished from that group by their 
exceptionally long malar spaces, which are at least one and one-half 
times as long as wide in the males and as long as wide in the fe- 
males. The great morphological diflFerences in other characters in- 
dicate that the rimmed m eta pleural protuberances, which are com- 
mon to the americanns group, may have been independently 
developed in productus. 

Male: length 9-11 mm,, wing length 6 mm. 

Pile of body very sparse, ochreus to pale grey; pile of face 
clumped principally about antennal bases and extending below to 
basal portion of clypeus; malar spaces and lower half of clypeus 
relatively free of hair and shiny; hair of vertex pale grey and sparse; 
lower genal areas with hairs sparse, long, and plumose; mesoscutura 
with pile sparse, ochreus to tawny yellow; scutellum with weak 
lateral and posterior fringe of pale grey pile; mesoscutum with 
ochreus pile extending down to posterior lobe of pronotimi having 
a few darker hairs among pale hairs on upper mesopleura; hair of 
mescpisterna very sparse, long, and branched, never sufficiently 
dense to conceal surface; upper lateral edges of prop odeum with 
a dense clump of pale grey hairs, lateral and posterior faces of 
propodeum free of pile; legs with short, pale grey pubescence even 
on posterior femora; first metasomal tergum with few sparse hairs 



202 The University Science Bulletin 

not concealing surface to any extent, but with weak lateral fringes 
of greyish pile; metasomal tergal fasciae narrow and weak, easily 
removed by rubbing; fasciae present on first to fifth metasomal 
terga; discs of metasomal terga three to six witli abundant^ short, 
erect, ferrugineous to blackish pile; sternal fasciae composed of a 
feWj sparse, apical, ochreus hairs. 

Antennae long, flagellar segments about one and one-half times 
as long as wide; malar spaces at least one and one-half times as 
long as wide; clypeus long, densely punctate basally, punctures be- 
coming sparser towards apex, lateroapical half shiny with very few 
punctures, clypeus flattened slightly medially with a weak furrow 
evident at base; elongate malar spaces and clypeus forming a snout- 
like extension to head; vertex shiny with few punctures. Protho- 
racic spines very short and sharp; anterior and posterior edges of 
pronotiim raised with shallowly concave disc, most evident at 
lateral edge; mesoscutiim black and shiny with very sparse, shallow 
punctures, punctures approximately three puncture widths apart 
even at anterior extremity of mesoscutum, mesoscutum with small 
impunctate area; scutellum with punctures coarse and dense on 
posterior half; mesex3istcrna shiny with obscure, shallow punctures 
on lower half, x>unctures becoming more distinct and much denser 
towards upper anterior face; metapleural prominences distinct but 
not reaching posterior margins of metapleura, rims dark brown, 
most conspicuous on anterior half; propodeum with lateral faces 
shiny, traversed by sharp rugae, lateroposterior edge abrupt, not 
rounded, with a weak ridge separating tlie two surfaces, basal area 
of propodeum witla shallow, quadrate pits; tegulae dark brown 
hyaline; wings dusky hyaline with scattered, fine^ ochreus pubes- 
cence most noticeable apically, nervures dark brown; legs black at 
bases, more brownish apically; hind basitarsi three times as long as 
wide. Disc of first metasomal tergum virtually impunctate, shiny; 
discs of terga two to four, shiny, and weakly folhculated. 

Female: length 10-11 mm., wing length 6-7 mm. 

Body black with a weak covering of hair on head and thorax, 
abdomen sparsely pubescent; hair of face sparse, concentrated 
chiefly about antenna! bases, vertex with a very few, pale grey hairs; 
pile of upper genal areas dense white to pale grey, becoming 
sparser and longer towards ventral faces; hair of mesoscutum 
ochreus and very sparse, not concealing surface; scutellum with a 
dense rim of pale ochreus pile on lateral and posterior edges; pos- 
terior lobes of pronotum with a dense mat of whitish to grey hair; 



Revision of the Bee Genus Colletes 203 

mesepisterna witla sparse, elongate^ branched pubescence^ not con- 
cealing surface; upper lateral surfaces of propodeum with dense 
clumps of ochreus hair; first metasomal tergum with but a few, long^ 
pale grey hairs on anterior face, very weak lateral fringes of hair 
on first tergum, which do not reach to fascia, fascia white and 
sharply narrowed medially; metasomal terga two to five with fasciae 
not narrowed as on first tergum, a slight widening of fasciae later- 
ally followed by an abrupt narrowing at extreme lateral margins; 
pile of legs short, moderately dense except on posterior femora^ 
where pile is long, curled, and pale grey; sternal fasciae absent; 
discs of metasomal terga three to six with short, dark ferrugineous 
to black pubescence giving surface an ironish tinge. 

Antennae short and dark, basal flagellar segment about as long 
as second; malar spaces at least as long as wide; clypeus shiny and 
sparsely punctate with large punctures over basal three-fourths^ 
becoming shiny impunctate on apicolateral portions, a weak longi- 
tudinal median furrow most pronomiced half way between base and 
apex; vertex shiny impunctate; fascial foveae deep, shiny im- 
punctate. Prothoracic spines short and blunt; pronotum expanded 
slightly laterally as a convex structure; mesoscutum witli shallow, 
sj>arsc punctures over surface, punctures at least tliree puncture 
widths apart, even on extreme anterior surface of mesoscutum, im- 
punctate area large and shiny; scutellum with deep, dense punc- 
tures over posterior half; mesepisterna with punctures shallow and 
obscure below, becoming deeper and denser towards the upper 
anterior portions, punctures on upper mesepisterna not more than 
one puncture width apart whereas those on posterior edges shallow 
and obscure; metapleural prominences strongly protuberant with 
dark brown rims, only slightly concave beneath; lateral faces of 
propodeum dull with a few, weak rugae near later oposteri or mar- 
gins, basal area with distinct, quadrate pits; tegulae dark brown; 
wings dusky hyaline with weak, ochreus pubescence on surface; 
legs dark brown to black at bases, tibiae and tarsi much more red- 
dish brown; posterior basitarsi wide and shallowly concave on up- 
per surfaces, about two and three-quarters times as long as wide. 
First metasomal tergum weakly and sparsely punctate, punctures on 
lateral portion of disc about two puncture widths apart, becoming 
shallower and sparser on anterior and mid portions of disc; second 
and third metasomal terga with very weak, dense, follicle-like 
punctures giving them a roughened yet shiny appearance. 

Distribution: Georgia: Margaret; Helen; Sarah. Alabama: Mo- 
bile;.Kushla. North Carolina: Bryson City; Grandfather Mountain; 



204 The University Science Bulletin 

Aberdeen; Old Fort Road; Raleigh; Roaring Gap. Kentucky: 
southeast Kentucky. Virginia: Falls Church. New Jersey: Lake- 
hurst, Massachusetts: HolUston; Needham. 

Flight records: May 10 to July 26, 

Plant records: Rhus glabra; Xolisma ligustrina. 

The holotype, apparently from Carlinville, Illinois, is in the col- 
lection of the Illinois Natural History Survey, 

Through the courtesy o£ L. K, Gloyd of tlie Illinois Natural History 
Survey J I have received the following information on the type of 

this species: 

"In the Trans. Am. Ent. Soc. for 1891, vol 18, on p. 49, Mr, Rob- 
ertson wrote 1 submit a synopsis of all the species which occur in 
my neighborhood (Carlinville, III) with notes on their time of 
flight and tlie flowers which they visit, as well as descriptions of 
new species'. So neither of the specimens from New Hampshire and 
Massachusetts at the University of Nebraska can be the holotype, 
Apparently Robertson placed the sign ^ or $ immediately follow- 
ing the species name at the beginning of his descriptions to indicate 
upon which sex the description was based. In the case of prodticttis, 
a ' $ ' follows the name but the last paragraph reads, 'One male, 
taken July 21st on flowers of Apocijnimi cannahimim! In the paper 
by Martin H. Muma, Bull Univ. Nebr. State Mus., vol 3, No. 8, 
1952, the type of Colletes productus is listed as a $ , So I tliink the 
^ specimen here must surely be the holotype/' 

Colletes arizonensis sp. nov, 

(Fig, 2) 

This new species from the mountains of Arizona resembles peri- 
leucus ratlier closely. The males have dark pile on the vertex, 
mesoscutum, and scutellum, and have tlie first metasomal tergum 
closely punctate. The females are rather distinctive in having 
lateroapical elevated ridges on the apical ventral metasomal seg- 
ment and abundant black pile on the thorax and head. An unusual 
character of both sexes is that the apical margin of the first meta- 
somal tergum is bluntly rounded raUier tlian with a broadly flattened 
fascial depression as on each of the remaming metasomal terga. 
The fascia of the basal tergum is composed of short, white pile at 
the extreme apex, 

Male: length 8.25 mm,, wing length 7 mm. 

Pile of face long and white, sparse over clypeus, partially con- 
cealing surface, a few dark hairs below antennal bases; vertex with 



Revision of the Bee Genus Colletes 205 

pile predominantly black, with a few pale gray to ochreus hairs inter- 
mixed; upper genal areas with pile short, pale grey, a few darker 
hairs intermixed on anterior face, pile becoming much longer, denser, 
and whiter below; mesoscutum with a sparse covering of pale grey 
and black pile, becoming more predominant on median discal area; 
scutellum with a very narrow peripheral fringe of fine, pale grey pile, 
abundant, long, black pile over mediolateral areas; mesepisterna 
with pile long, white to pale grey, and fine; propodeum witli tufts of 
long pile at upper later oposterior margins, pile with a strong ad- 
mixture of black hairs, lateral and posterior faces witli long, fine, 
pale grey, erect x^ile; first metasomal tergum with an apical fringe 
of short, white pubescence, not lying in a depressed fascia, lateral 
fringes of white pile short, reaching apical fascia, disc with abundant, 
short, erect, whitish pile, not at all concealing surface; metasomal 
terga two to five with fasciae nairow, weak, and white; metasomal 
terga four to six with abundant, erect, short, black pile on discs; 
metasomal sterna two to five with weak apical fringes of white to 
pale grey pile- 
Antennae deep reddish brown to black, flagellar segments one 
and one-half times as long as broad; malar spaces one-half as long 
as broad; clypcus weakly convex with a shallow, longitudinal me- 
dian sulcus, surface weakly, striately punctate, punctures most dense 
along clypeof rental regions and down median sulcus, i)^^iictures 
of lateral faces striate and separated by shiny interspaces; vertex 
shiny, impunctate. Prothoracic spines short and sharp, about as 
long as width across base; mesoscutum coarsely punctate over an- 
terior one-half and lateral margins, impunctate area large; scutellum 
with a few coarse fji^ii^^tures about lateral and posterior margins^ 
median discal area very sparsely punctate with broad, shiny inter- 
spaces, anterior one-half virtually impunctate; mesepisterna deeply 
punctate with shiny interspaces, punctures one-half puncture width 
ax^art; propodeum with basal area very shallowly, quadrately pitted, 
lateral and posterior faces shiny and rather sharply punctate; tegulae 
black; wings dusky with abundant, very short, fine, deej> fulvous 
pubescence, nervures deep brown; legs deep brown to black; pos- 
terior basitarsi four times as long as broad. First metasomal tergum 
densely punctate on lateral and apical margins, punctures fine and 
no more than one puncture width apart, j)unctLires becoming very 
sparse and much finer on median and medioaj)ical faces where 
they are four to five puncture widths apart, apical margin not de- 
pressed to retain fascia, rather abruptly rounded with a very weak 



206 The University Science Bulletin 

preapical groove; second metasomal tergum densely, coarsely follic- 
ulated, follicles about one follicle width apart; metasomal sterna 
shiny; seventh ventral plates much as in productus, however with 
laterobasal projection blunt and weakly rounded (fig* 2). 

Female: length 10 mm,, wing length 7.75 mm. 

Pile of face ratlier sparse, concentrated chiefly about antennal 
bases and along lower inner orbital margins, a few darker hairs 
intermixed below antennal bases; vertex with pile predominantly 
black, a few pale grey to dusky hairs intermixed; upper genal areas 
with pile short and pale grey, with a few longer, black hairs inter- 
mixed, pile becoming longer, whiter, and finer below; mesoscutum 
with a sparse covering of pale grey and black pile^ black pile pre- 
dominating on median disccil area; scutellum with a narrow lateral 
and posterior fringe of white pile, having abundant, erect, black 
pile medially; mesej^isterna with an admixture of pale grey and 
black pile on preepisterna and on upper mesepisterna, pile becoming 
longer and pure white below; propodeum with long tufts of inter- 
mixed black and pale grey pile on dorsal surface of lateroposterior 
margin, lateral and posterior faces with abundant, erect, pale grey 
pile; femora and tibiae of middle and hind pairs of legs with pile 
long and tinged with fulvous; abundant, short, black pile inter- 
mixed particularly on upper surfaces of tibiae; first metasomal 
tergum with a dense ax:>ical fringe of short, white pubescence, lateral 
fringes very weak and white, barely reaching fascia, disc with 
abundant, erect, whitish pile; metasomal terga two to four with 
fasciae narrow, white, and weak; metasomal terga three to five 
with abundant^ erect, deep fulvous to black pubescence; metasomal 

sterna with sparse, erect, pale grey pile, particularly on apical one- 
thh'd of each sternum. 

Antennae brown below, black above, long, flagellar segments 
about as long as wide; malar sf)aces three-eighths as long as wide; 
clypcus flattened with a deep longitudinal median sulcus, clypeus 
sparsely, coarsely, striately punctate, punctures one to three puncture 
widths apart, with broad, shiny interspaces; vertex shiny, impunctate; 
fascial foveae very deep, broadened slightly medially, extending 
above inner orbital margins, reaching almost half way from inner or- 
bital margins to lateral ocelli. Froth or acic spines short and sharp, 
about as long as width across tlie base; mesoscutmii coarsely and 
densely punctate about anterior one half and lateral margins, im- 
punctate area small; scutellum finely, almost contiguously punctate, 
about extreme lateral and posterior faces, punctures becoming sparse 



Revision of the Bee Genus Colletes 207 

in median discal area and absent on anterior one-tliird; mesepisterna 
densely and coarsely punctate, punctures no more than one-halt 
puncture width apart with shiny, linear interspaces; propodeum 
with basal area very shallowly, quadrately pitted, lateral and pos- 
terior faces with numerous, sharp punctures, surface moderately 
shiny; tegulae deep brown to black; wings dusky, very densely 
covered with deep fulvous pubescence, nervures deep brown; legs 
deep brown to black; posterior basitarsi three and three-fourths 
times as long as broad. First metasomal tergum very finely punctate 
about lateral and apical margins^ punctures becoming exceedingly 
fine and sparse on median and medioapical surfaces where they 
appear to be folliculated rather than punctured; second metasomal 
tergum densely and finely folliculated; metasomal sterna dull, 
densely folliculated, last metasomal sternum with weak, elevated, 
lateral ridges, extending about apicolateral margins to posterior 
margin cutting off a narrow, shiny apical rim. 

Distribution: Holotype, male, south slope Tumacacori Mountain, 
8 miles west of Nogales, Arizona, 6000 feet, in the chaparral zone, 
July 20, 1949 (F. Werner and W, Nutting); allotype, female, tox3 
of Huachuca Mountains, Arizona, August 10^ 1940 (E, S. Ross); 
parat>^pes: 2 males, south slope of Tumacacori Mountain, 8 miles 
west of Nogales, Arizona, 6000 feet, chaparral zone, July 20, 1949 
(F. Werner and W. Nutting); 1 female, tojD of Huachuca Mountains, 
Arizona, August 10, 1940 (E, S, Ross), 

The holotype is in the collection of the Musuem of Comparative 
Zoology at Harvard University and tlie allotype is in the collection 
of the California Academy of Sciences, 

Colletes perileuctis Cocker ell 

(Fig. 5) 

Colletes periJeucus Cockerell, 1924, Proc. California Acad. Sci,, ser, 4, vol. 12, 
p. 535j Tlmberlakej 1951^ Wasmann 1. BioL, vol. 9, p. 202. 

The species, originally described from a female from Guaymas, 
Son or a, Mexico, has been recorded from California by Timberlake. 
The present work extends the range to Arizona and southwestern 
Texas. It is difficult to separate the females of penleucus and olho- 
cinctus; however, peril eiic us has the prothoracic spines very long 
and sharp, and the second metasomal tergum not depressed basally. 
There is some doubt as to the correct association of the sexes of 
albocincttis and it is not at all impossible that the female designated 
as alhocinctus may prove to be a subspecies of perileucus. The 
males of the two species are markedly different, penleucus having 



208 The University Science Bulletin 

the malar spaces one-half as long as wide and the first metasomal 
tergiim shiny and iinpunctate, whereas in alhocincttis the malar 
spaces are slightly longer than wide and the first metasomal tergum 
is densely, coarsely punctate. The males of perileiicus are dis- 
tinguished from arizonensis by having the black pile only on the 
scutellum and in having the first tergum shiny and impunctate. The 
females are readily distinguished from closely related species by 
having black pile restricted to the vertex, mesoscutum, and scutel- 
lum, and also by the impunctate condition of the first metasomal 
tergum, 

Male: length 10 mm., wing length 7,5 mm. 

Pile of face long, dense, and pure white^ completely concealing 
clypeus and lower face; vertex with pile long and pale grey; upper 
genal areas with pile long, dense, and pale grey, becoming much 
whiter and finer below j mesoscutum with pile long, dense, and 
dusky; scutellum with a dense covering of long pile, particularly 
about lateral and posterior margins, pile dusky on extreme peri- 
pheral edge, strongly admixed with black medially; mesepisterna 
with pile long, fine, and white; propodeum with dense fringes of 
white pile on lateroposterior margins from dorsal face to pedicel, 
lateral and posterior faces with abundant, very long, white pile; 
pile of legs sparse, short, and white; first metasomal tergum with a 
dense, broad, white apical fascia^ lateral fringes of long, white pile 
extending to apical fascia, disc with abundant, long^ erect, white 
to pale grey pile, partially obscuring the surface medially; meta- 
somal terga two to five with fasciae narrow but pure white; meta- 
somal terga four to six with abundant, erect, deep fulvous to black 
pubescence, not at all concealing surface; metasomal sterna two to 
five with dense apical fringes of white pile. 

Antennae long and brown, flagellar segments one and one-half 
times as long as broad; malar spaces five-eighths as long as broad; 
clypeus Weakly convex, rather densely and finely punctate, par- 
ticularly on clypeofrontal margins and down median longitudinal 
line J punctures coarser on axiicolateral faces and tending to be some- 
what striate; vertex dull, densely and deeply punctate* Prothoracic 
spines long and sharp, at least one and one-half times as long as 
width across base; mesoscutum densely punctate over anterior and 
lateral margins, punctures becoming sparse medially, impunctate 
area large; scutellum coarsely punctate over posterior one half, 
punctures becoming finer anteriorly to absent on extreme anterior 
face, punctures not at all striate; mesepisterna with punctures shal- 



Revision of the Bee Genus Colletes 209 

low, coarse, one-half puncture width apart above to one puncture 
width apart below, interspaces shiny; propodeum with basal area 
not at all pitted, weakly roughened, lateral and posterior faces dull 
and weakly roughened; tegulae brownish hyaline; wings very weakly 
dusky with very sparse, deep fulvous pubescence apically^ nervures 
brown; legs deep brown to black; posterior basitarsi four times as 
long as broad. First metasomal tergum shiny, sparsely foUiculated, 
surface with a very deep bluish-black metallic lustre; metasomal 
sterna sparsely and finely folliculated; seventh ventral plates broad 
and elongate with median and lateral edges rcflexed^ much as in 
product us (fig. 5). 

Female: lengtli 11.5 mm,, wing length 8 mm. 
Pile of face short, white, and dense, particularly between antennal 
bases and compoimd eyes; vertex with abundant, back pile, with a 
few intermixed pale grey hairs; upper genal areas with pile pre- 
dominantly short, pale grey, with a few intermixed, longer, black 
hairs, pile becoming much longer, finer, and whiter below, a wide 
band of appressed, white pubescence immediately posterior to each 
compound eye; mesoscutum with anterior and lateral margins 
having pile short, dense, and white, discal area with abundant, 
black hair intermixed; scutellum with a narrow fringe of pale grey 
pile about peripheral margins, median discal area predominantly 
covered with black pile; mesepisterna with pile long, fine, and 
white; propodeum witli dense fringes of long, white pile on latero- 
posterior margins^ extending down lateroposterior margins toward 
pedicle, lateral and posterior faces with sparse covering of long, 
erect, white pile; pile of anterior two pairs of legs short and white, 
posterior legs with pile long, plumose, and tinged with light och- 
reus; first metasomal tergum with apical fascia broad and pure 
white, weakly interrupted medially, lateral fringes of long, white 
pile just barely reaching apical fascia, disc with abundant, long, 
erect, whitish pile; metasomal terga two to four with fasciae broad, 
rather dense, and white; metasomal tergum five with a very nar- 
row apical white fascia; second metasomal tergum with a broad 
basal fascia, remnants of a white basal fascia just evident on third 
metasomal tergum; metasomal terga four and five with abundant, 
erect, black pile on discal areas; metasomal sterna witli weak apical 
fringes of short, white pile, usually interrupted medially, discs of 
metasomal sterna with a few, erect, pale grey hairs, not at all scopa- 
like- 
Antennae brown, flagellar segments about as long as broad; malar 



210 The University Science Bui^letin 

spaces one- third as long as broad; clypeus very weakly convex with 
a longitudinal median sulcus^ surface coarsely but rather sparsely 
punctate with punctures one to two puncture widths apart, most 
densely punctate along median sulcus, interspaces shiny; vertex 
fnoderately shiny with numerous^ very shallow^ fine punctures; fas- 
cial foveae deep, slightly broadened medially, extending dorsally 
above inner margins of compound eyes, dorsal margins extending 
but one third of the way to lateral ocelli. Prothoracic spines very 
long and sharp, approximately three times as long as width across 
the base; mesoscutum densely punctatCs punctures one-half to one 
puncture width apart over anterior one half and lateral margins, 
impunctate area large; scutellum rather coarsely punctate over 
posterior one half, punctures sparser and finer, becoming absent, 
on anterior face, punctures not at all striate; mesepisterna closely, 
coarsely, and deeply punctate, punctures no more than one-half 
puncture width apart with shiny interspaces; propodeum with basal 
area very finely rugate, not at all quadrately pitted, dull, lateral 
faces shiny and finely marked, posterior face dull and weakly rough- 
ened; tegulae brownish hyaline; wings dusky with a moderate cover- 
ing of deep fulvous pubescence, especially apically, nervures dark 
brown; k^gs deep reddish brown; posterior basitarsi four times as 
long as broad. First metasomal tergum shiny, impunctate except 
for a few, very shallow, sparse follicles, surface tinged with a deep 
bluish-black lustre; second metasomal tergum shiny, rather densely 
and very finely folliculated; metasomal sterna shiny, coarsely and 
very sparsely folliculated, follicles one to four follicle widths apart. 

Distribution: 1 female, Guaymas, Mexico, April 7, 1921 (E. P, 
Van Duzee) (cotype); 3 males, El Mayor, Baja California, April 
1939 (C. D. Michener); 1 female, Wild Rose Canyon, Panamint 
Mountains, Inyo County, California, 7500 ft.. May 28, 1937 ( C. D. 
Michener), on Prosopis jidiflora glandulosa; 1 female^ Tombstone to 
Bisbee, Arizona, over 4500 ft., June 16, 1942 (H. A. Scullen); 1 male, 
2 females. Big Bend Park, Hot Springs, Texas, Ax>ril 11, 1949 
(Michener-Beamer), on Prosopis juliflora. 

The sj>ecies has been taken on flowers of mesquite, Prosopis jtili- 
flora, and Timber lake also records a single specimen taken at the 
flowers of Melilotus, As far as present records indicate, perileuciis 
appears to be a spring and early summer species. 

The holotype from Sonora, Mexico, is in the California Academy 
of Sciences, 



Revision of the Bee Genus Colletes 211 

Collet es cercidii Timberlake 

( Fig. 3 ) 
Colletes cercidii Timberlake, 1951, Wasmann J, BioL, vol 9, pp* 198-200. 

This and the following species, C. rudis Timberlake, deviate 
slightly from the typical members of the prodiictus group and are 
placed here witli some hesitancy. The seventh ventral plates and 
the genital capsules resemble those of the prodticttis group except 
for certain specific characters. Both sexes of cercidii bear some re- 
semblance to skitmeri Viereck and gilensis Cockerell, but do not 
have the coarse puncturation of either species* The males have tlie 
malar spaces one-half as long as vi^ide; dark pile intermixed on the 
vertex J mesoscutum^ and scutellum; and the first metasomal tergum 
finely punctate. The females are similar to skinneri, but have the 
malar spaces shorter, the first metasomal tergum more finely punc- 
tate, the second metasomal tergum weakly depressed basally, and 
the second and third terga with faint basal fasciae, 

Male: length 10 mm., wing length 7,75 mm. 

Pile of face very long, dense, and white, completely concealing 
clypeus and antennal basal region; vertex with pile long and sparse, 
strongly intermixed with black; genal areas with upper surface 
having sparse, short, pale grey pile with a few dark hairs inter- 
mixed on anterior margins, pile becoming much longer, finer, and 
whiter below; mesoscutum with pile i>redominantly pale grey to 
white, particularly about lateral and anterior faces^ abundant, black 
pile intermixed over discal area, being most dense on median por- 
tions of disc; scutellum with a narrow fringe of pale grey pile about 
lateral and posterior faces, discs with pile predominantly long and 
black; mesepisterna with pile long, fine, and white; propodeum 
with long fringes of white X3ile on dorsal lateroposterior margins, 
lateral and posterior faces with abundant, long, erect, pale grey 
pile; legs with pile short, sparse, and white; first metasomal tergum 
with apical fascia broad, dense, and white, lateral fringes of long, 
white pile extending to apical fascia, disc with abundant, erect, 
whitish pile; metasomal terga two to five with fasciae broad, dense, 
and white; metasomal terga four to six with discs having abundant, 
short, black, erect pile; metasomal sterna two to five having apical 
fringes of long, pale grey pile, pile much shorter medially. 

Antennae long, reddish brown to brown, flagellar segments one 
and one-half times as long as broad; malar spaces one-half as long 
as broad; clypeus flattened medially with a very shallow, longitudinal 
median line, surface finely and densely punctate over basal one- 



212 The University Science Bulletin 

half, punctures becoming much more striate apically^ striate punc- 
tures extending virtually to apex; vertex shiny, sparsely punctate^ 
punctures one to three puncture widths apart* Protlioracic spines 
absent; mesoscutum densely and coarsely punctate over anterior and 
lateral margins, punctures one-half puncture width apart, impuiic- 
tate area small; scutellum rather densely and coarsely punctate over 
posterior three-quarters, anterior face shiny ^ im punctate; mesepi- 
sterna with punctures coarse and dense, having shiny interspaces, 
punctures one-half puncture width apart; propodeum with the basal 
area not at all pitted, having a few, very weak, irregular rugae, 
lateral and posterior faces dull and roughened; tegulae deep brown; 
wings dusky with abundant, deep fulvous pubescence, nervures 
brown; legs deep brown to black; posterior basitarsi four and one- 
fourtli times as long as broad. First metasomal tergum finely and 
rather densely punctate, punctures coarser laterally, becoming much 
finer on median surface, punctures one to two puncture widths 
apart; metasomal terga two and three coarsely and rather densely 
folliculatedj interspaces shiny; second metasomal tergum very 
weakly depressed basally; metasomal sterna shiny, coarsely and 
sparsely folliculated; seventh ventral plates broadly subtriangular, 
with apical margins extended and rounded, median margins strongly 
reflexed, with basal hair bands extending across base and down 
median reflexed margins (fig. 3). 

Female: length 11.5 mm., wing length 8.5 mm. 

Pile of face short and dense, particularly about antennal bases 
and along lower inner orbital margins; mesoscutum with pile palj 
grey about anterior and lateral faces w^tli abundant, deej) black 
pubescence on median discal area; scutellum with a very narrow 
fringe of pale grey pile about lateral and posterior faces, disc with 
abundant, erect, black pile; inesepisterna with pile long, fine, and 
pale grey; propodeum with dense fringes of long, pale grey pile 
on upper lateroposterior margins, extending down toward j^edicel, 
lateral and posterior faces with abundant, erect, pale grey pile; 
anterior two pairs of legs with pile long and white, posterior pair of 
legs with abundant, long, plumose pile on femora and tibiae, 
strongly tinged with ochreus; first metasomal tergum with a very 
weak, white fascia^ broadly interrupted medially, tergum with den.e 
lateral fringes of white pile extending to fascia, disc with abundant, 
erect, pale grey pile; metasomal terga two to four with the fasciae 
weak, broad, and white, occasionally interrupted or partially inter- 
rupted medially; metasomal terga four and five with abundant, short, 



Revision of the Bee Genus Colletes 213 

deep fuscous to blacky erect pile on discal areas; metasomal sterna 
two to four with very weak fringes of pale grey pile, discal area 
with abundant, erect, light ochr eus pile, forming a weak scopa on 
metasomal sterna two and three. 

Antennae long and reddish brown ^ flagellar segments one and 
one-eighth times as long as broad; malar spaces one-tliird as long 
as broad; clypeus flattened medially, very densely, coarsely, striately 
punctate to apex, interspaces shiny , a very faint trace of a median 
longitudinal sulcus; vertex shiny, sparsely punctate, with punctures 
one to three puncture widths apart with shiny interspaces; fascial 
foveae narrow and deep, curved at dorsal extremity toward lateral 
ocelli, inner margin of curve reaching just barely over one third of 
way from inner orbital margins to lateral ocelli. Prothoracic spines 
very shorty vestigial; mesoscutum very coarsely and densely punc- 
tate over anterior and lateral mai;gins, impunctate area very small, 
with punctures much sparser over median discal area; scutellum 
densely, finely, contiguously punctate about extreme lateral and pos- 
terior margins, punctures becoming much coarser and sparser to- 
ward anterior face, where they vary from one-half to one puncture 
width apart, anterior one third shiny, impunctate; mesepisterna 
deeply and densely punctate, with shiny interspaces, punctiux^s one- 
half puncture width apart; propodeum with basal area smooth, very 
shallowly flitted, pits not at all uniformly quadrate^ lateral and pos- 
terior faces roughened, dull; tegulae deep brow^n to black; \M*ngs 
dusky with abundant, deep fulvous pubescence, nervures dark 
brown; legs dark brown to black; posterior basitarsi three and 
tliree-fourths times as long as broad. First metasomal tergum 
finely and densely punctate, with shiny interspaces, punctures ap- 
proximately one puncture width apart, punctures of apical and me- 
dian faces much finer than lateral discal areas; second metasomal 
tergum very finely and densely folliculated, surface dull, second 
metasomal tergum with a weak basal depression; metasomal sterna 
shiny, coarsely and densely folliculated. 

Distribution: Timberlake records the holotype male and the allo- 
type female from Box Canyon^ Riverside County, California, on 
March 31, 1934, on Cercidium torreyamim, and tlie following para- 
topes on tire same flower: 2 males and 2 females. Box Canyon, 
March 31 and April 13, 1934; 1 female, Oasis, Riverside County, 
March 27, 1934; 1 female, Gila Bend, Arizona, March 28, 1934 
(Timberlake); 1 female, Morristown, Arizona, May 21, 1945; 1 male, 
Potholes, Imperial County, California, April 10, 1923 (E, P. Van 
Duzee ) . 



214 The University Science Bulletin 

I have seen the male paratype from Box Canyon, April 13, 1934, 
the female paratype from Gila Bend, Arizona, and the male para- 
type from Potholes, The types are in the collection of the Citrus 
Experiment Station, Riverside, California. 

Colletes rudis Timberlake 

( Fig, 4 ) 
Colletes rudis Timberlake, 1951, Wasmann J, Biol, vol. 9, p. 197. 

The species is described from two males taken at Indio, Cali- 
fornia. It is a rather unique species with roughly quadrate seventh 
ventral plates. There is a slight resemblance to C. prodtictus but 
rudis has only a few black hairs on the posterior portion of the 
scutellum; the malar spaces are shorter, approximately three-fourths 
as long as wide; and the metapleural prominences are absent, 

Male: length 10 mm.^ wing length 7 mm. 

Pile of face long, dense^ and white, completely concealing clypeus 
and antennal bases; vertex with pile rather dense and tinged with 
grey J a few darker hairs intermixed; genal areas with upper surfaces 
having abundant, short, pale grey pile, pile becoming much longer, 
finer, and whiter below; mesoscutum with pile long, dense^ and 
predominantly pale grey, a few darker (not black) hairs interimxed 
on median discal area; scutellum with very dense lateral and pos- 
terior rims of pale grey pile, pile having a few black hairs inter- 
mixed; in esepis tenia with pile long, fine, and white; propodeum 
with long, pale grey fringes of pile on upper lateroposterior margins, 
lateral and posterior faces widi abundant, erect, pale grey pile; legs 
with pile shorty sparse, and white; first metasomal tergum with 
apical fascia broad and white, lateral fringes of pale grey pile weak, 
barely reaching to apical fascia, disc with abmidant, erect, pale grey 
pile; metasomal terga two to four with fasciae broad, weak^ and 
pure white; fascia of fifth metasomal tergum very weak, evident 
only as an apical fringe of fine, white pile; metasomal terga tliree to 
six witla abundant, very short, black, erect pubescence, not at all 
concealing surface; metasomal sterna two to five with long apical 
fringes of white pile, pile somewhat shortened medially. 

Antennae long, deep brown to black, flagellar segments one and 
one-fovnth times as long as broad; malar spaces three-fourths as long 
as broad; clypeus weakly convex, flattened medially, very finely and 
densely punctate over basal three-fourtlis, punctures becoming 
somewhat striate and much sparser on lateroapical margins; vertex 
dull, densely and deeply punctate. Prothoracic spines very short; 
mesoscutum very coarsely and densely punctate over anterior and 



Revision of the Bee Genus Colletes 215 

lateral faces, impuiictate area very small with numerous coarse 
punctures lying irregularly on median area; scutellum finely, densely, 
contiguously punctate about lateral and posterior edges, punctures 
becoming coarser and sparser anteriorly, never more than one- 
half pimcture width apart to anterior face; mesepisterna coarsely, 
densely, almost contiguously punctate, with shiny, linear interspaces, 
interspaces becoming dull below; propodeum with basal area shal- 
lowly, irregularly, quadrately pitted, lateral and posterior faces dull 
and roughened; tegulae deep brown to black; wings with abundant, 
deep fulvous pubescence, nervures brown; legs black; posterior 
basitarsi four times as long as broad. First metasomal tergum 
densely pimctate with moderately fine punctures, punctures becom- 
ing much sparser and finer medially and on anterior portions, x)unc- 
tures approximately one-half to one puncture width apart laterally; 
second metasomal tergum very densely and finely punctate or 
coarsely folliculated, punctures one-half to one puncture width 
apart; metasomal sterna shiny, finely and sparsely folliculated; 
seventh ventral plates roughly quadrate with lateral and median 
margins weakly reflexed (fig. 4). 

Disfribution: One male, 5% miles west of Indio, Cafifornia, Feb- 
ruary 18, 1946 (P. H, Timberlake), at the flowers of Encelia farinosa 
( holotype ) . 

I have only seen the holotype. However, Timberlake records a 
male paratype taken at the same time and place as the holotype. 
The types are in the collection of the Citrus Experiment Station, 
Riverside, California* 

* Colletes giJensis Cockerell 

(Fig. 6) 

Colletes gilensis Cockerell^ 1897, Ann, Mag, Nat. Hist., ser. 6, vol 19, p. 41; 
1897, Bull New Mexico Agric. Exper Sta., no, 24, p. 24; 1898, Bull Deni- 
son Univ., vol 11, p, 42; 1898, Bull Univ. New Mexico, vol 1, p. 42; 1899, 
Entom,, vol 32, p, 155; 1901, Ann. Mag. Nat. Hist,, ser. 7, vol 7, p. 125; 
1901, Ent. News, vol 12, p. 41; 1902, Amer. Nat., vol 36, p. 810; 1904, 
Entom., vol i37, p. 6; 1906, Trans, Amer. Ent. Soc, vol 32, p, 292; Swenlc, 
1908, Univ. Nebraska Studies, vol 8, p. 23; CockereH, 1909, Psyche, vol 
12, p. 87; Gibson, 1914, Rept Ent. Soc. Ontario, p. 124 (out of known 
range); Timberlake, 1943, Bull. Amer, Mus. Nat. Hist, vol 81, p* 398. 

The species occurs in the southwestern part of the United States 
and in northern Mexico, from Colorado south to New Mexico and 
Arizona and east to the Big Bend country of Texas. It can be dis- 
tinguished by its very large size and the very coarse puncturation 
of the metasomal terga, but may be confused with compact us Cres- 
son. The males, however^ have short malar spaces, about one-half 



216 The Uni\^rsity Science Bulletin 

as long as broad, and the female lacks the elevated ridges on the 
last metasomal sternum. 

Male: length 14 mm., wing length 10 mm. 

Face with pile coarse, dense, and pure white, completely con- 
cealing the clypeus, a few darker hairs along inner orbital margins; 
vertex with mixture of black and light pile; genal areas with upper 
surfaces having a few black hairs but predominantly white, pile 
becoming very long, white, and plumose on lower surfaces; meso- 
scutum with strong mixture of black pile; scutellum with abundant, 
long, black and x>ale grey pile on posterior and lateral faces; mesepi- 
sterna with long, fine, plumose pile, white below with a few black 
hairs on pre~episterna; propodeum with dorsolateral margins with 
dense clump of long, pure white pile, lateral and posterior faces 
with abundant, very fine, erect, white pile; legs with pile white, 
sparse, and long; metasomal terga one to five with broad, dense, 
white apical fasciae; metasomal tergum one witli lateral fringes of 
pure white pile to apical fascia, disc and anterior face with abun- 
dant, fine, erect pile; metasomal tergum two with few, very fine 
hairs over basal portion; metasomal terga three to six with abundant, 
short, black, erect discal pile; metasomal tergum six lacking apical 
fascia; metasomal tergum seven with deep brown, appressed pile; 
metasomal sterna two to five with broad apical fasciae of pure white 
pubescence, broadest medially on terga two to four; metasomal 
sterna three to five with abundant, long discal pile tinged with 
ochre us. 

Antennae long and brown, flagellar segments one and one-half 
times as long as broad; malar spaces one-half ^ as long as broad; 
clypeus weakly convex with sharp median longitudinal sulcus, sulcus 
with close punctures, lateral cl>T^eal areas coarsely and densely 
punctate over basal half, punctures sparse with broad shiny inter- 
spaces apically; vertex densely punctate with shiny interspaces. 
Prothoracic spines long and sharp, about one and one-half times the 
width across the base; mesoscutum densely and coarsely punctate, 
punctures contiguous to one-half puncture width apart over anterior 
and lateral margins, impunctate area small; scutellum with anterior 
one-fourth shiny and sparingly punctate, posterior three-fourths 
coarsely and densely punctate to posterior margin where punctures 
are contiguous; niesepisterna coarsely and densely punctate with 
shiny interspaces, tending to striately punctate above; propodevnn 
having basal area broad with weak, quadrate pits, lateral and pos- 
terior faces dull, roughened, and weakly rugose; tegulae deep 



Revisiok of the Bee Genus Colletes 217 

brown; wings dusky with abundant, long, brownish pubescence 
over apical half, nervures brown; legs dark brown; posterior basi- 
tarsi four and one-half times as long as broad. Metasomal tergum 
one coarsely and densely punctate^ punctures no more than one- 
half puncture width apart, a weak median longitudinal impunctate 
ridge transversing disc, extreme apical margin raised as a flange-like 
apex with a shallow pre apical groove^ most evident at medial area; 
metasomal terga two and three densely and coarsely punctate^ punc- 
tures one-half to one puncture width apart; metasomal tergum two 
sharply depressed b as ally; metasomal terga three to six with punc- 
tures of variable coarseness with shiny interspaces; metasomal sterna 
shiny and sparsely folliculated or weakly punctate; seventh ventral 
plates transversely quadrate with laterobasal process long (fig. 6). 

Female: length 14,5 mm.j wing length 11 mm. 

Face with pile sparse, white, and erect, a few hairs overhanging 
clypeus from frontoclypeal suture; vertex with mixture of long black 
and shorter pale grey pile; genal areas with upper surfaces having 
mixture of black and pale grey pile, becoming longer and much finer 
to pure white below; mesoscutum with mixture of black and pa^e 
grey pile extending to extreme anterior surface; scutellum with 
strong covering of long, black pile intermixed with shorter, finer, 
pale grey hairs particularly about extreme margins; mesepisterna 
with pile long, fine, and pure white, a few darker hairs on pre- 
ej)isterna; propodeum with dense lateroposterior clumps of long, 
white pile, lateral and posterior faces with few, scattered, long, fine, 
white hairs; anterior pair of legs with long, white femoral pile, 
tibiae and tarsi with pile tinged with ochreus, second and third pairs 
of legs with pile tinged with ochreus, a few, short, spinelike hairs on 
upper surface of posterior tibiae; metasomal terga one to five with 
dense, white apical fasciae, much narrowed on tergum five; meta- 
somal tergum one with long lateral fringes of white pile, disc and 
anterior face with few, short, fine hairs; second metasomal tergum 
with weak basal fascia; metasomal terga three and four with few, 
short, white hairs forming rudiments of weak basal fascia; meta- 
somal terga two to five with discal areas having short, black, erect 
pubescence; metasomal tergum six with pile golden to brown and 
appressed; metasomal sterna with apical margins having few, short, 
fine, white hairs, discal areas witli abundant, fine, erect pile tinged 
with ochreus* 

Antennae reddish brown, flagellar segments as long as broad; 
malar spaces three-eighths as long as broad; clypeus weakly convex 



218 The Uni\trsity Science Bulletin 

with median longitudinal sulcus not reaching apex or base, sulcus 
with few, coarse, contiguous punctures, lateral faces coarsely and 
striately punctate, closely punctate about base and sparsely punc- 
tate with broad shiny interspaces apically; vertex shiny ^ finely punc- 
tate; fascial foveae narrow and long, broadened sharply medially, 
dorsal portions pointed and curved, reaching two thirds of the way 
to lateral oceUi. Prothoracic spines long, about one and one-half 
times as long as width across base; mesoscutum densely and coarsely 
punctate, punctures no more than one-half puncture width apart 
about anterior and lateral margins, impunctate area small; scutel- 
lum with anterior one fourth shiny and sparingly punctate, posterior 
three fourths becoming more densely and finely punctate toward 
posterior margins; mesepisterna coarsely and densely punctate with 
punctures becoming much finer on posterior faces , almost rugosely 
punctate with shiny interspaces; propodeum with basal area broad, 
shallowly, quadrately pitted, lateral and posterior faces dull and 
weakly roughened; tegulae brown; wings dusky with abundant, long, 
brownish pubescence over apical one third, nervnres brown; legs 
brown; posterior basitarsi three and one-third times as long as broad. 
Metasomal tergum one coarsely and densely punctate, punctures 
varying from one-half to one puncture width apart, apical margin 
reflexed slightly with a shallow preapical groove most evident 
medially, shallow longitudinal median impunctate ridge; meta- 
somal tergiuu two with punctures deep and sparser than on tergum 
one, basal area sharply depressed, apical margin slightly reflexed; 
metasomal tergum three with punctures shallow, finer, and sepa- 
rated by one to three puncture widths; metasomal terga four and 
five shiny and finely punctate; metasomal sterna shiny, coarsely 
folliculated, apical margins hyaline, impunctate- 

Distribution: Colorado: Pueblo; Grand Junction; Colorado 
Springs; Boulder; Greeley; Halls Valley* New Mexico: Las Vegas; 
White Mountains; Gila; Jemez Springs; Socorro County. Arizona: 
Oak Creek Canyon; Huachuca Mountains; Grand Canyon; Flag- 
staff. Texas: Davis Mountains; Chisos Mountains^ Big Bend Na- 
tional Park. 

Flight Records: This appears to be an aestival species, occurring 
from June 15 to August 21, 

Plant records: Melilotus alha, Petalostemnm candidus, P, ffave- 
scens, P. oUgopJujUns, Potentilla thurberi, SoUdago canadensis. 

The type of this species, a male from West Fork of the Gila River, 



Revision of the Bee Geistus Colletes 219 

New Mexico, has not been located. It was last recorded in the 
Cockerell collection. 

Colletes skinneri Viereck 

(Fig. 7) 

Colletes skmneri Viereck, 1903, Trans. Amcr. Ent. Soc, vol. 29, p. 58; Cockerell, 
1905, Psyche, vol 12, p. 86; 1906, Bulk Amer, Mus. Nat. Hist., vol 22, p. 
425; 1906, Trails. Amer. Ent. Soc, vol 32, p. 291; Swenk, 1908, Univ. 
Nebraska Studies, vol 8, p. 21; Cresson, 1928, Mem. Anier Ent. Soc, no. 5, 
p. 64. 

This species is most likely to be confused with C. gilensis or van- 
dykei Timberlake, However, both sexes can be readily distin- 
guished by the mahir spaces, which surpass both the aforementioned 
species in length. The malar spaces of ttie male are approximately 
one and three-eighths times as long as broad, and those of the 
female three-quarters as long as broad, much longer than its closest 
relative, gilensis, in which these spaces are almost linear, 

Male: length 10 mm., wing length 7.5 mm. 

Pile of face long, most dense about antennal bases, clypeus in- 
completely concealed with a long, overhanging fringe of pile from 
clypeo frontal regions, pile mostly pale grey with a few darker hairs 
intermixed below and mesad to antennal bases; vertex witli a 
mixture of dark and pale grey pile, sparse; genal areas with a weak 
covering of short, pale grey to light ochreus pile above, pile becom- 
ing much longer, denser, and finer below; mesoscutum with a strong 
admixture of black pile, particularly on median discal area, pile 
about anterior and lateral faces predominantly pale grey to tinged 
with yellowish; scutellum with a narrow fringe of pale grey pile 
about lateral and posterior faces, pile of disc predominantly black; 
mesepisterna with a sparse covering of long, fine pile, pile tending to 
grey to tinged with ochreus above, becoming much whiter to pale 
grey below; propodeum wvith long fringes of dusky pile along upper 
lateroposterior margins, lateral and posterior faces with abundant, 
long erect, pale grey pile; legs with pile long, sparse, and pale grey; 
first metasomal tergum with apical fascia weak and white, broadly 
interrupted medially, lateral fringes of pale grey pile weak, barely 
extending to apical fascia, disc with abundant, erect, pale grey 
pile; metasomal terga two to five with fasciae weak and pure 
white, often interrupted medially; metasomal terga three to six 
with discs having abundant, very short, black pile intermixed 
with a few, longer, pale grey hairs, not at all concealing surface; 
metasomal sterna two to four with narrow apical fringes of white 
to pale grey pile. 



220 The University Science Bulletin 

Antennae deep reddish brown, flagellar segments one and one- 
third times as long as broad; malar spaces one and three-eighths 
times as long as broad; clypeus convex with a longitudinal median 
sulcus, ratlier densely and coarsely, striately punctate about latero- 
frontal regions and down longitudinal median sulcus, lateroapical re- 
gions sparsely punctate with broad, shiny interspaces; vertex deeply 
and coarsely punctate with shiny interspaces, punctures contiguous 
to one-half puncture width apart; compound eyes weakly petiolate 
as viewed from above. Pro thoracic spines very short and sharp; 
mesoscutum densely and coarsely punctate over anterior one half 
and lateral margins, punctures no more than one-half puncture width 
apart, impunctate area small; scutellum densely and coarsely 
punctate over posterior two tliirds, punctures contiguous except 
along median longitudinal line, anterior face sparsely punctate to 
virtually impunctate; mesepis tenia densely, weakly striately punctate 
above, dull, punctures becoming less striate on lower faces and 
interspaces more shiny; propodeum with basal area being shallowly 
and quadrately pitted^ lateral and posterior faces dull and roughened; 
tegulae brownish hyaline; wings dusky, very densely covered with 
a deep fulvous pubescence, nervures dark brown; legs reddish 
brown to black; posterior basitarsi four times as long as broad. 
First metasomal tergum very densely and coarsely, almost con- 
tiguously punctate over entire surface, punctures slightly sparser 
along median anterior face^ surface rather dull; second metasomal 
tergum densely punctate^ punctures one-half to one puncture width 
apart, being much finer and denser medially and basally; metasomal 
sterna shiny^ sparsely and weakly folliculated; seventh ventral 
plates closely resembling those of gilensis but having median fringe 
much longer and denser (fig. 7)* 

Female: length 11 mm., wing length 8 mm. 

Pile of face long, white to pale grey with a few darker hairs inter- 
mixed below antennal bases; clypeus with a weak covering of 
overhanging, pale grey pile; vertex with pile predominantly long 
and black amongst finer, pale grey hairs; genal areas with abundant, 
erect, pale grey pile, pile becoming much longer^ finerj and whiter 
below, with a very weak rim of short, ajjpressed, white pubescence 
immediately posterior to each compound eye; mesoscutum with 
abundant, black pile intermixed with pale grey, black pile becoming 
most predominant on median discal area; scutellum with a lateral 
and posterior fringe of long, pale grey pile, discal area covered with 
erect, black pile; mesepisterna with pile long, fine, pale grey to 



Revision of the Bee Genus Colletes 221 

white; propodeum witli long fringes of white to pale grey pile on 
lateroposterior margins, extending down toward the pedicel, lateral 
and posterior faces with pile long, fine, and erect; pile of anterior 
two pairs of legs has long, white fringes from the femora, posterior 
legs with pile rather sparse, long, plumose, and tinged with ochreus, 
particulai'ly on femora and tibiae; first metasomal tergum with apical 
fascia narrow and white, broadly interrupted medially, lateral 
fringes of pale grey pile weak and barely reaching apical fascia, disc 
with si:)arse, erect, whitish jDile, pile short; metasouKil terga two to 
five with fasciae white and broad, sharply narrowed medially; meta- 
somal terga three to five with abnndant, erect, black pile on discal 
areas, pile becoming much longer on apical terga; metasomal sterna 
with very weak fringes of short, pale grey pile on extreme apical 
margins. 

Antennae brown, flagellar segments about as long as broad; malar 
spaces three-fourths as long as broad; clypeus weakly convex, flat- 
tened medially to having a very weak, longitudinal median groove, 
clypeus rather coarsely and densely striately punctate about clypeo- 
frontal regions and along median depressed sulcus, lateroapical 
portions shiny and very sparsely punctate; vertex densely punctate 
with shiny interspaces; fascial foveae sharply delineated, narrow, 
curving inward from dorsal margins of compound eyes toward 
lateral ocelli, reaching almost one-half way to lateral ocelli from 
upper inner orbital margins, Prothoracic spines short and heavy; 
mesoscutnm very densely and coarsely punctate over entire surface, 
punctures no more than one-half puncture width apart, impunctate 
ai"ea absent; scutellum with extreme posterior and lateral margins 
finely, contiguously punctate, dull, punctures much coarser over 
discal area with shiny, linear interspaces, scutellum punctate to 
anterior margin, a weak longitudinal median groove extending length 
of scutellum; mesepisterna densely, weakly striately punctate, punc- 
tures no more than one-half to one puncture width apart, surface 
dull; propodeum with basal area narrow and very shallowly pitted, 
lateral and posterior faces dull and roughened; tegulae deep brown; 
wings dusky with abundant, fulvous pubescence, nervures brown; 
legs brownish black; posterior basitarsi four times as long as 
broad. First metasomal tergum very densely and coarsely punctate, 
punctures one-half to one puncture width apart except on a median 
longitudinal impunctate line where punctures are very sparse to 
absent, interspaces shiny; second metasomal tergum very finely 
punctate or coarsely folliculated, interspaces shiny; metasomal sterna 



222 The University Science Bulletin 

coarsely and rather densely folliculated on apical half of each 
sternum, surface shiny. 

Distribution: One female, Beulali, New Mexico (Skinner) (holo* 
type); 1 male, Beulah, New Mexico, August IS (T. D. A. Cockerell) 
(allotype); 1 female, Catalina Mountains, Arizona, August 21, 1942 
(E. C, Van Dyke). 

The holotype from New Mexico is in the Academy of Natural Sci- 
ences of Philadelphia, 

CoUetes vandykei Timberlake 

( Fig, 8 ) 
CoUetes vandykei Tmiberlake, 1951, Wasmann J. BioL, vol, 9, p, 200. 

This species is based on a single male taken from the Santa Rita 
Mountains of Arizona. It is similar to arizonensis^ differing in its 
exceptionally large size and in having abundant, black pile extend- 
ing well down the mesepisterna. The apical margins of the first 
metasomal terga in both species are very similar in that the fasciae 
do not lie in abrui)tly depressed margins but rattier fringe a broadly 
rounded apex, in both species there is evidence of a very narrow 
and weak pre apical groove, particularly laterally. Genitalically the 
species is very similar to arizonensis^ skinnen, and gilensis. The 
seventh ventral plates of vandykei are much more distinctly quad- 
rate than either of the above-mentioned species and have the latere- 
basal projections much shorter and blunter. 

Male: length 13 mm., wing length 9.25 mm. 

Pile of face long about antennal bases and along lower inner 
orbital margins, with a strong admixture of black pile immediately 
below antennal bases; clypeus covered partially by an overhanging 
fringe of pale grey pile; vertex with a mixture of black and pale 
grey pile, particularly in ocellar triangle; upper genal areas with 
pile predominantly pale grey, however having a few darker hairs on 
anterior face, pile becoming much longer, finer^ and pure white 
below; mesoscutum strongly covered with a mixture of black and 
pale grey pile, black predominating medially; scutellum with but a 
very narrow, lateral and posterior fringe of pale grey pile, discal 
area with abundant, long, black x:>ile; mesepisterna witli an ad- 
mixture of pale grey, dark, and black pile on upper half, pile pre- 
dominantly hght to pale grey below; propodeum with very dense 
fringes of black and white pile on upper lateroposterior margins, 
dense fringes extending down toward pedicel and becoming whiter 
ventrally, lateral and posterior faces with abundant, erect, dusky 
pile; pile of legs short, sparse, and predominantly white, with a 



Revision of the Bee Genus Colletes 223 

weak admixtvire of black pile most evident on fringes of prcfemora; 
first metasomal tergiim with a narrow apical fascia of pure white 
pile, interrupted medially, lateral fringes of pale grey pile weak, 
barely reaching apical fascia, disc with abundant, very short, whitish 
pile; metasomal terga tv^^o to four with narrow, white apical fasciae, 
broadly interrupted medially; metasomal terga five and six with 
abundant, erect, black pile on the discal areas; metasomal sterna 
two to five with very weak apical fringes of pale grey pile. 

Antennae deep brown to black, flagellar segments one and one- 
fourth times as long as broad; malar spaces one-half as long as broad; 
clypeus convex, weakly flattened medially, surface very coarsely, 
striately punctate about laterobasal edges and down a median longi- 
tudinal line to apex, lateroapical portions shiny, impunctate; vertex 
densely punctate, punctures contiguous to one puncture width apart, 
interspaces shiny. Prothoracic spines very short and sharp, about 
as long as width across base; mesoscutum very densely and coarsely 
punctate, punctures almost contiguous on anterior two-thirds and 
lateral margins, impunctate area absent; scutellum densely and 
coarsely punctate over entire surface, a deep longitudinal median 
groove running to anterior margin, mesepisterna with punctures 
coarse and dense, one-half to one puncture width apart with inter- 
spaces shiny; propodeum with basal area having a number of weak, 
longitudinal rugae, not at all forming quadrate pits, lateral and pos- 
terior faces dull and roughened; tegulae deep brown to black, rather 
finely and densely punctate; wings dusky with abundant, deep 
fulvous pubescence, nervures dark brown; legs black; posterior basi- 
tarsi four times as long as broad. First metasomal tergum densely 
covered with moderately coarse punctures, punctures much finer 
than those of mesoscutum and approximately one puncture width 
apart, interspaces shiny, apical margin very weakly reflexed, giving 
it a blunt, rounded appearance and also giving an impression of a 
very shallow, x>i^eapical groove, most evident laterally; metasomal 
terga tw^o, three, and four very coarsely and sparsely folliculated, 
follicles varying from one to three follicle widths apart, interspaces 
shiny, black; metasomal sterna shiny, coarsely and sparsely follicu- 
lated; seventh ventral plates much more quadrate than eitlier 
skinneri or gilensis and having laterobasal projections short and 
blunt (fig. 8)^ 

Distribution: One male, Madera Canyon, Santa Rita Mountains, 

Arizona, August 15, 1940 (E, C, Van Dyke) (holotype). 

The type is in tlie collection of the California Academy of Sciences. 



224 The University Science Bulletin 

Group II — compactus 

Collet e$ compactus compactus Cresson 

(Fig, 9) 

Colletes compacta Cresson, 1S68, Proc. Boston Soc, Nat. Hist., vol 12, p, 166; 
Pattoii, 1879, Proc. Boi^ton Soc. Nat. Hist,, vol 20, p, 142; Robertson, 1895, 
Trans. Anier. Ent. Soc, vol 22, p. 115; Viereck, 1903, Ent, News, vol 14, 
p. 120; Robertson, 1904, Canadian Ent., vol 36, p. 275; Cockerell, 1905, 
Psyche, vol 12, p. 86; Robertson, 1906, Science, voL 23, p. 309; Lovell, 
1907, Can. Ent., vol. 39, p, 363; Swenk, 1908, Univ. Nebraska Studies, vol. 
8, p. 25; Smith, 1910, Ann. Rept. New Jersey State Mus. for 1909, p, 694; 
Robertson, 1914, Ent. News, vol, 25, p. 70; Viereck, 1916, Conn. GeoL Nat. 
Hist. Bull., vol. 22, p. 740; Cresson, 1916, Mem. Amer. Ent. Soc, no. 1, p. 
107; Ran and Ran, 1916, J, Animal Behaviour, voL 6, p. 367; Rau, 1922, 
Trans. Acad. Sci. St, Louis, vol. 24, p, 37; Criddle et a/., 1924, Rept. Ent. 
Soc, Ontario, p. 99; Robertson, 1926, Psyche, vol. 33, p. 116; 1926, Ecology, 
vol. 7, p, 378; Leonard, 1926, Cornell Agric. Exper. Sta. Mem., no. 101, p. 
1021; Robertson, 1928, Flowers and Insects, p. 10; Pearson, 1933, Ecolog, 
Monogr., vol 3, p, 384; Brimley, 1938, Insects of North Carolina, p. 451; 
Timberlake, 1943, Bull Amer, Mus, Nat. Hist., vol. 81, p. 400. 

This is one of the more robust forms of the genus and is dis- 
tributed throughout North America south of the Boreal zone. The 
male is readily distinguished by the long malar spaces and deep 
median longitudinal sulcus of the clypeus, and the female has 
strong elevated lateral ridges on tlie last metasomal sternum. There 
is a progressive decrease in the ratio of black to white pile from the 
type locality in the east to the western part of tlie Great Plains, but 
through this range the black pile of the thoracic dorsum is evident* 

Male: length 11 mm,, wing length 8 mm. 

Face with pile long and dense about antennal bases, much shorter 
and appressed along lower inner orbital margins^ abundant, long, 
white pile overhanging clypeus from frontoclypeal suture and con- 
ceaHng upper and lateral surfaces; inner orbital margins with mix- 
ture of long, black hairs below antennal bases; vertex with mixture 
of black and light ochreus hairs; genal areas with upper surfaces 
with mixture of black and dusky pile, becoming longer, denser^ and 
pure white on lower surfaces; mesoscutum witli mixture of long, 
weakly plumose, dusky and black pile, black pile predominating 
over posterior portions of disc; scutellum with pile very long, plu- 
mose, and mostly black; mesepistema with pile pale grey, weak ad- 
mixture of black hairs above and on pre-episterna; propodeum with 
strong lateroposterior fringes of pale grey pile, lateral and posterior 
faces with abundant, long, erect, pale grey pile, not concealing sur- 
face; legs with pile sparse, fine, and white; metasomal terga one to 
five with broad apical fasciae weakly covered with pure white, 
short pubescence; metasomal tergum one with fascia narrow, almost 



Revision of the Bee Genus Colletes 223 

absent medially, lateral fringes of long, white pile, discal area and 
anterior face with abundant, fine, erect pile; metasomal terga four 
to six with scattered, long, erect, ferrugineous hairs; metasomal ter- 
gum seven with pile brown^ appressed; metasomal sterna two to five 
with broad apical fasciae of pure white pile. 

iVntennae long and brown, flagellar segments one and three- 
fourths times as long as broad; malar spaces as long as broad; cly- 
pens long with a deep longitudinal median sulcus bordered by two, 
lateral, shiny, sparsely punctate rims, a few shallow punctures along 
medial sulcus; vertex dull, sparsely and weakly punctured with nar- 
row, shiny interspaces. Prothoracic spines short and sharps about 
as long as the width across the base; mesoscutum densely and 
coarsely punctate with punctures one-half to one puncture width 
apart on anterior and lateral faces; scutellum with anterior one-half 
impunctate except for a few, shallow, puncturelike depressions, sur- 
face shiny, posterior one-third closely and densely punctate with 
punctures contiguous on posterior margin; mesepisterna coarsely 
and closely punctate, punctures about one puncture width apart 
with shiny interspaces; propodeum with basal area broad, not pitted 
but with irregular striae, lateral and posterior faces finely rough- 
ened, not striate or rugose; tegulae light brown; wings whitish 
hyahne with scattered, fine, light pubescence apically, nervures 
brown; legs reddish brown; posterior basitarsi five and one-half 
times as long as broad. Metasomal tergum one densely and coarsely 
punctate over entire surface, punctures almost contiguous wdth 
linear, shiny interspaces; metasomal tergum two with punctures 
deep and coarse as first tergum but separated by one to two punc- 
ture widths, basal area sharply depressed, apical fascia in smooth 
hyaline depression most evident laterally; metasomal terga three to 
six shiny, weakly punctate or folliculated; metasomal sterna shiny, 
finely and densely folliculated apically; seventh ventral plates 
roughly quadrate, with median, lateral, and basal margins reflexed, 
discs densely covered with pile (fig, 9). 

Female: length 13 mm*, wing length 9 mm. 

Face with strong mixture of black and pale grey pile about an- 
tennal bases and lower frontal regions; clypeus bare; except for a 
few overhanging hairs from frontoclypeal margin; vertex with pile 
long, predominantly black with finer, intermixed, pale grey hairs; 
genal areas with upper surfaces having black pile predominating, 
pile becoming longer, denser, and pure white on lower surfaces; 
mesoscutum with dense covering of black and white pile; scutellum 

8—1542 



226 The University Science Bulletin 

with pile long and black about anterior and lateral margins; mes- 
ex>isterna with pile long, white, and plumose, a few dark hairs on 
extreme upper surfaces; propodeum with lateroposterior margins 
with strong fringe of pale grey to light ochreus pile, occasionally 
with a few, scattered, dark hairs, lateral and posterior faces with 
few, fine, light hairs; legs with pile white, except on posterior 
femora and tibiae where it is tinged with ochreus and having some 
short, spinelike, dark hairs on upper faces; metasomal tergum one 
with weak apical fascia only evident laterally; metasomal terga two 
to four with fasciae broad, pure white, and weak; metasomal terga 
three to five with a few, erect, long; brown hairs on discs; metasomal 
tergum six with pile deep brown to black and appressed; metasomal 
sterna with a few, light ochreus hairs along apical margins. 

Antennae brown, flagellar segments as long as broad; malar 
spaces three-eighths as long as broad; clypeus with median portion 
flattened to weakly concave-, surface roughened and dull with scat- 
tered, coai'se, shallow punctures separated by one to two puncture 
widths; vertex finely and densely punctate with shiny interspaces, 
Prothoracic spines absent; mesoscutum coarsely and densely punc- 
tate over anterior half and lateral margins, punctvires almost con- 
tiguous, median impunctate discal area large; scutellum with ante- 
rior two thirds shiny, impunctate, posterior one third with punctures 
obscure and dense; mesepisterna coarsely and densely punctate 
with shiny interspaces; propodeum with basal area broad, not 
pitted but with numerous longitudinal striae, lateral and posterior 
faces dull and weakly roughened; legs deep reddish brown; pos- 
terior basitarsi three and three-fourths times as long as broad; meta- 
somal tergum one with disc finely and densely punctate, punctures 
varying from one -half to one puncture width apart; metasomal ter- 
gum two with disc very finely punctate, pimctures approximately 
one puncture width apart and slightly smaller than those on tergum 
one, apical fascia in sharply declivous hyaline depression; meta- 
somal terga three to five with discs shiny, weakly punctate or follicu- 
lated; metasomal sterna two to four coarsely and sparsely follicu- 
lated^ one to three follicle widths apart, apical margins light hyaline; 
last metasomal sternum with two, strongly elevated, lateral ridges 
extending from base to apex^ converging slightly and most pro- 
nounced apically. 

Distrihution: The subspecies is found throughout America south 
of the Boreal zone and east of the Great Divide, occurring in great- 
est abundance in the eastern, particularly seaboard, portions of the 



Revision of the Bee Genus Colletes 227 

United States and Canada. On the basis of present collections, 
c. compacfus is not known to occur in the deep south, but a male 
from Flagstaff^ Arizona, as well as material from Meadow Valley, 
Mexico, suggests that the species may extend along the foothill 
regions into the Arizona and Mexican plateaus. 

Marginal localities inckide: Roundhill, Nova Scotia; St. John, 
New Brunswick; Bryson City, North Carolina; Atlanta, Georgia- 
Ozark Lake^ Missouri; Manhattan, Kansas; southern Arizona; Mi- 
waukee, Wisconsin; and Midland County, Michigan, 

Flight records: The species has been recorded as flying between 
July 10 (New Jersey )and November 11 (North Carolina), reaching 
its maximum abundance during September and early October. 

Plant records: Aster midtiflorus and Solidago sp. are the only two 
plants this bee has been recorded as visiting. Robertson suggests 
it is oligotropic on Compositae. 

The types from Connecticut and Illinois are in the Academy of 
Natural Sciences of Philadelphia. 

Colletes compact as hesperius Swenk 

Colletes hesperius Swenk, 1906, Ent* News, vol, 17, p. 257. 

Colletes compacfus hesperius, Swenk, 1908, Univ. Nebraska Studies, voL 8, p. 

28; Gibsun and Griddle, 1921, 50th Kept. Ent, Soc. Ontario, p. 131. 
Colletes compactus, Tiiiiberlake (not Gresson), 1951, Wasmann J. Biol, vol, 9, 

p. 196. 

The form, originally described by Swent in 1906, was reduced 
to subspecific rank in 1908, C, c, hesperius has the black pile of the 
body reduced and even absent in some cases^ and although there is 
considerable variation in size, both sexes are larger than their 
eastern counterparts. There is some question as to the exact area 
of intergradation of these tvvo subspecies, for specimens from Flag- 
staff, Arizona; Meadow Valley, Chihuahua, Mexico; and Golden, 
Colorado, all exhibit characters intermediate between the Wash- 
ington type and typical c. compacttis. A single male taken at Flag- 
staff, Arizona, resembles c. compactus closely except for a slight re- 
duction in the amount of black pile present on the head and thoracic 
dorsum. Another male from Murray, Utah, has the black pile ab- 
sent from the head and present only on the mesoscutum and scutel- 
lum; this cline appears to terminate in the more northerly specimens 
from Washington and British Columbia, which have the pile of tlie 
body all white except for a few dark hairs on the scutellum. The 
length and density of the pile of the body varies inversely with the 
presence of black. 



228 The University Science Bulleten 

In the females this feature is even more evident. Although I have 
seen no Arizona material, two females from Escalante and Bryce 
Canyon, Utah, have a strong admixture of black pile on the meso- 
scutum and vertex. The ratio of black to white decreases in material 
from northern Utah and southern Oregon, where the pile of the 
inner orbital margins is tawny grey to dusky and that of the vertex 
dusky with a few black hairs intermixed. 

The single female from Chimney Gulch, Golden, Colorado, de- 
viates strongly from c. compactus of the western plains and bears a 
close resemblance to material from Washington and British Colum- 
bia, for there is no black pile on the vertex nor along the inner orbital 
margins and the pile of the mesoscutum is predominantly dusky to 
tawny grey. 

Male: Similar to c. compactus except in having inner orbital mar- 
gins with a few dark hairs, not black; mesoscutum and scutellum 
with few black hairs; apical metasomal fasciae broader and denser; 
malar spaces one and one-fourth times as long as broad. 

Female: As in c. compactus except in having face with no dark 
pile and much larger ( 14-15 mm. ) ; vertex with few to no black hairs; 
mesoscutum and scutellum with black pile restricted to median dis- 
cal area; malar spaces slightly longer, about one-half as long as 
broad; second metasomal tergum sharply depressed basally, con- 
taining a broad basal fascia at least as wide as apical fascia. 

Distribution: Aiizona: Flagstaff. Utah: Bryce Canyon; Esca- 
lante; Murray; Springville; Granger; Taylorsville; Mills. Idaho: 
Parma, California; Old Station, Shasta County; Gazelle, Siskiyou 
County; Mohave Desert. Oregon: Echo; Rufus, Sherman County. 
Washington: Hunt's Junction; Almota, Whitman County; Yakima. 
British Columbia: Oliver; Walhachin; Vernon; Penticton; Lillooet; 
Okanagan. Colorado: Chimney Gulch, Golden. 

Flight records: The species has been taken between August 30 

and October 15. 

The types from Almota, Whitman County, Washington, are in the 

collections of the University of Nebraska. 



Revision of the Bee Genus Colletes 229 

Gboup III — latitarsis 

Colletes latitarsis Robertson 

(Fig. 10) 

Colletes latitarsis Robertson, 1891, Trans. Amer. Ent, Soc, voL 18, p, 60; 1892, 
Trans. Acad. Sci, St. Louis, vol 5, p. 571; 1904, Canadian Ent., vol. 36, 
p. 275; 1906, Science, vol 23, p, 309; Swenk, 1908, Univ, Nebraska Studies, 
vol. 8, p. 17; Graenicher, 1910, Bull, PubL Mus, Milwaukee, vol 1, p. 228; 
Banks, 1912, Eiit, News, vol 23, p, 107; Robertson, 1926, Ecology, vol 7, 
p. 387; 1926, Psyche, vol 33, p. 116; Leonard, 1926, Cornell Agric. Expen 
Sta, Mem., no. 101, p. 1021; Robertson, 1928, Flowers and Insects, p, 10; 
Graenicher, 1930, Ann, Ent. Soc, Amer., vol 23, p. 154; Pearson, 1933, 
Ecolog. Monog., vol 3, p. 384; Gracniclier, 1935, Ann. Ent, Soc, Amer., 
vol 28, p, 301; Erimley, 1938, Insects of North Carolina, p. 45L 

This species is distinctive but may be confused with iviUistoni 
Robertson. The males can readily be distinguished by having the 
posterior basitarsi two and one-fourth times as long as broad and 
by having tlie fifth sternal segment with its posterior margin strongly 
curved anteriorly froai two posterior lateral angles. The female 
has the second tarsal segment of each hind leg short, approximately 
as long as broad, whereas the same segment in iciUistoni is one and 
one-half times as long as broad. In the female of latitars^is the pos- 
terior basitarsi are very broad, about two and one-fourth times as 
long as broad and the posterior tibiae are clothed with a mixture of 
grey and black pile. 

Male: length 9.5 mm., wing length 6.23 mm. 

Face with pile pure white, long, and dense about antennal bases 
and along inner orbital margins; clypeus bare except for a few long 
hairs overhanging from lateral margins; vertex with a few, dark, 
long hairs, but predominantly short, white pile; genal areas with 
pile pure white, becoming much longer and whiter on lower regions; 
mesoscutum with strong admixture of black and white pile; scu- 
tellum with the disc predominantly covered with black pile, lateral 
and posterior margins with fringe of longer ^ pure white pile; mes- 
episterna with the pile long, fine, and white; propodeum with strong 
clump of black and white pile on lateroposterior margins, lateral 
and posterior faces of propodeum with short, white pile not con- 
cealing surface; anterior femora and tibiae with very long, white 
pile, second and third pairs of legs with the pile short, sparse, and 
pale grey; metasomal terga one to five with broad, white apical 
fasciae; first metasomal tergum with dense lateral fringes of white 
pile extending to fascia, anterior face and discal area with abundant, 
erect, fine, white pile not concealing surface; metasomal terga two 
to five with abundant, short, deep fuscous to black pile on disc; 



230 The University Sqence Bulletin 

metasomal tergiim six with pile semiappressed and deep golden; 
metasomal stema one to five with apical fringes of ochreus pile, 
almost comblike; tergosternal margins with abundant black pile; 
metasomal sternum five with apical fringe of deep fuscous to black 

pile. 

Antennae short, reddish brown, middle flagellar segments short, as 
long as broad; malar spaces seven -eighths as long as broad; clypeus 
flattened with shallow longitudinal median sulcus, surface shiny 
with a number of obscure longitudinal punctures; vertex shiny with 
scattered fine punctures, Prothoracic spines long and sharp, longer 
than width across base; mesoscutum closely and coarsely punctate^ 
punctures almost contiguous over entke surface with shiny, almost 
linear, intersx)aces, impunctate area absent; scutellum with anterior 
surface sparsely jiimctate with fine punctures, punctures becoming 
coarser and more dense toward posterior margin, interspaces shiny; 
mesepisterna deeply and coarsely punctate, punctures almost con- 
tiguous above, tending to one-half punctiu^e width apart below; 
propodeum with basal area deeply, quadrately pitted, lateral and 
posterior faces shiny and weakly stria te^ posterior face separated 
from lateral by weak longitudinal striae; tegulae deep brown; wings 
dusky with abundant, short, fine, brown j>i^^t>^scence, nervures 
brown; legs brown; posterior basi tarsi two and one- fourth times as 
long as broad, Metasomal terga one and two deeply punctate with 
punctures varying from one to two puncture widths apart, becoming 
finer and denser toward extreme apical margins; metasomal terga 
three to five shiny and weakly foUiculated; metasomal sterna shiny 
with apical margins of metasomal terga three and four weakly 
emarginate medially; metasomal sternum five strongly excavated 
from two lateral margins; seventh ventral plates as illustrated 
(fig, 10). 

Female: length 10 mm., wing length 6 mm. 

Face with pile white, short, and concentrated principally along 
lower inner orbital margins; clypeus bare; vertex with mixture of 
black and white pile; genal areas with pile short and pure white; 
mesoscutum with mixture of black and white pile over entire disc; 
scutellum with the disc completely covered with short, black pile, 
lateral and posterior margins with a fringe of short, white pile; 
mesepisterna with pile fine and white; pre-episterna with mixture 
of black and white pile; propodeum with lateral and posterior faces 
having abundant, short, white pile not concealing surface, latero- 
posterior margins with strong clump of pure white pile; legs with 
pile pale grey to deep fuscous, posterior femora and tibiae with pile 



Revision of the Bee Genus Colletes 231 

mainly black; metasomal terga one to four with apical fasciae pure 
white; first metasomal tergum with weak lateral fringes of white 
pile, disc with few, fine, white, erect hairs; metasomal terga three 
to five with discs covered with short, fine, erect, black pile; meta- 
somal tergum six with pile semiappressed, black to deep golden; 
metasomal sterna witli mixture of erect, black and ochreus x>ile, not 
fasciated- 

Antennae brown, short; flagellar segments three-fourths as long 
as broad; malar spaces one-third as long as broad- clypeus flattened 
with a deep median longitudinal sulcus, shiny with elongate obscure 
punctures; vertex shiny and sparsely punctate. Prothoracic spines 
long and sharp, longer than width across base; mesoscutum very 
coarsely, densely punctate with punctures one-half puncture width 
apart, almost contiguous on extreme anterior and lateral faces, 
impunctate area absent; scutellum wn'th punctures smaller on an- 
terior one third, becoming larger and much more dense toward 
posterior face; mesepisterna shiny, deeply punctate with punctures 
approximately one-half puncture width apart; propodeum with the 
basal area deeply, quadrately pitted, lateral and i^osterior faces dull 
and finely striate; tegulae deep brown; wings dusky with abundant, 
fine, brown pubescence, nervures brownish black; legs reddish 
brown; posterior basitarsi two and one-half times as long as broad; 
second tarsal segment of hind leg as long as broad at widest points. 
Metasomal tergum one closely and deeply punctate over entire sur- 
face, becoming finer and denser on extreme apical margins; meta- 
somal tergum two with punctures much finer and denser than those 
of first; metasomal terga three to five densely folliculatt d; meta- 
somal sterna dull and finely and densely folliculated; metasomal 
sterna four and five with apical margins emarginate medially. 

Disfrihtition: The species is sparingly distributed over eastern 
America to the tablelands of Arizona. Marginal areas include: 
Forsythe, Montana; Pierre, South Dakota; Faribault, Minnesota; St. 
Croix County, Wisconsin; Douglas Lake, Michigan; South Miami^ 
Florida; West Point, Mississippi; Quemada, Texas; Huachuca, Ari- 
zona; and Wray, Colorado. 

Flight records: Records from Florida and Texas indicate the 
species begins flying in March and continues until August, With 
the increase in latitude to the north and altitude to the southwest 
the emergences are retarded with the latest seasonal record as Sep- 
tember 29 from a Carlinville, Illinois, specimen. The main flights 
occur during July, August, and early September. 



232 The Untvebsity Science Bulletin 

Plant records: The bee i^rincipally visits members of the genus 
Physalis but is not oHgotropic on that group. Records include: 
Asclepias incarnata^ Ceanothus americantis^ Medicago sativa^ MeU- 
lotus alba, Physalis lanceolata, P. virginiana. Polygonum hydropiper, 
SoUdago, and Symphoricarpos occidentalis. 

Specimen number 8987, a female, bearing a "Type" label printed 
in red, is hereby designated lectotype, and a male, lacking a num- 
ber and collection data but bearing a written "Type" label, is des- 
ignated lecto allotype. 

The lectotypes from lUinois are in the collection of the Illinois 
State Natural History Survey. 

Colletes punctipennis maurus subsp, nov, 

(Fig. 11) 

Colletes punctipennis, CockereU (not Cresson), 1914, Ann, Mag. Nat. Hist*, 
sen 8, vol 14, p. 11; 1917, Ann. Mag. Nat, Hist., ser, 8, voL 19^ p. 48 L 

This species was originally described by Cresson from specimens 
taken in Mexico south of Mexico Citj^ An examination of die origi- 
nal description and of a male from Yucatan convinces me that Texas 
specimens exhibit sufficient differences to merit subspecific recogni- 
tion. The pile of the face, niesothorax, and tibiae is strongly inter- 
mixed with black pile whereas p. ptmctipennis has no black hair in 
these areas. The prothoracic spines of p. maurus are shorter and 
more nearly triangular and the puncturation of the vertex is more 
distinct. Generally the pile of the body has a much greater inter- 
mixture of black in the Texas specimens, and the isolation of this 
subtropical area in the Brownsville region may restrict the dark 
pox^ulation to a very small locale. 

Male: length 11.5 mm., wing length 8,5 mm. 

Pile of face predominantly long and white about antennal bases 
and along inner orbital margins; clypeus with a few, overhanging, 
long, pale grey to white hairs^ a strong admixture of erects black pile 
later ad and ventrad to antennal bases; vertex with pile black mixed 
among finer, pale grey pile; upper genal areas with pile short, pale 
grey, with a few dark intermixed hairs, pile becoming much longer^ 
denser^ and whiter below; mesoscutum wdth a very strong ad- 
mixture of black and pale grey pile over entire surface; scutellum 
with pile predominantly black except for a weak peripheral fringe 
of white pile; mesepisterna with an admixture of black and pale 
grey pile above^ pile becoming longer, finer, and whiter below; 
propodeum with a dense fringe of long, pale grey and black pile 
at upper later oposterior surfaces, lateral and posterior faces with 



Revision of the Bee Genus Colletes 233 

pile shorter and whiter; pile of legs long and rather sparse with al- 
most equal quantity of black and white pile intermixed; first meta- 
somal tergum with apical fascia very weak and narrow, often in- 
terrupted medially, pile forming a weak white fringe, lateral fringes 
of pile weak, short, and white, barely reaching apical fascia^ disc 
with sparse, erect, i>ale grey pile; metasomal terga two to four with 
fasciae very weak, narrow, and white, often interrupted medially; 
metasomal terga two to six with abundant^ erect, black pile on discal 
areas; metasomal sterna with a weak covering of fine, dark pile, 
particularly on apical portions of each sternum* 

Antennae long, yellowish brown below to deep brown-black 
above; malar spaces five-eighths as long as broad; clypeus with a 
deep longitudinal median sulcus, most evident at central portion, 
surface very coarsely, striately punctate to apex, interspaces shiny; 
vertex dull, finely and densely pimctate; fascial foveae distinctly 
depressed above, barely reaching to top of inner margin of com- 
pound eyes. Prothoracic spines roughly triangular, barely as long 
as width across base; mesoscutum very coarsely and densely punc- 
tate, almost contiguous anteriorly to one-half puncture width apart 
posteriorly, impunctate area absent; seutellum very densely and 
coarsely punctate to anterior margin, punctures contiguous and not 
at all striate; mesepisterna deeply, coarsely punctate, punctures one- 
half puncture width apart with shiny interspaces; propodeum with 
basal area deeply, longitudinally quadrate, lateral and posterior 
faces dull and roughened; tegulae deep brownish black; wings 
dusky with abundant, long, deep fulvous pubescence over entire 
surface, wings pictured, pictures extending posterior to the stigma 
and apically from radial sector to anteroapical margin, weakly 
pictured about apical ends of veins, median one and cubitus one; 
legs exixemely robust, deep black; posterior basitarsi twice as long 
as broad. First metasomal tergum very densely and coarsely punc- 
tate, punctures one-half to one puncture width apart, interspaces 
shiny, a weak elevated median impunctate longitudinal ridge; 
second metasomal tergum with punctures slightly finer and denser 
than those of first tergum, not more than one-half puncture width 
apart, tergum abruptly depressed basally; apical fasciae of meta- 
somal terga two to four lying in smooth, black, impunctate margins; 
metasomal sterna with apical portions finely folficulated, discal areas 
shiny; seventh ventral plates and capsule complex, much as in 
latit arsis (fig. 11). 

Distribution: Holotype, male, Brownsville, Texas, July 3, 1938 
(R. H, Beamer); paratypes, 3 males, Brownsville, Texas, October 



234 The University Science Bulletin 

16, 1908 (Mitchell and Bishop); Palm Forest, Brownsville, Texas, 
March 27, 1951 (R. H. Beamer); Brownsville, Texas, January 2 tol3, 
1928, 

The holotype is in the Snow Entomological Collections of the 
University of Kansas, 

Group IV — simulans 

Collet es simulans Cresson 

This species most closely resembles fulgidus Swenk, particularly 
in the western part of its range, where the females are at times 
barely distinguish able. The mountain representatives of simulans 
differ slightly from fulgidus in having the puncturation of the first 
metasomal tergum much closer and coarser; however, there are 
exceptions to this, and the only accurate method of determination 
is by genitalic examination of the males. The penis valves of 
simulans are broad, truncate apically, and the gonostyli are slightly 
more than four times as long as their apical width. In fulgidus the 
penis valves are weakly rounded and the gonostyli are three times 
as long as broad measured at the same position. The seventh ventral 
plates of simulans vary greatly in the regions between the western 
part of the Great Plains and California. Generally they are much 
broader and have long lateral basal projections near the basal hair 
tufts in the west and north. As Timberlake suggests, the trapezoidal 
shape of the seventh ventral plate is exaggerated in the Swenk illus- 
tration from CaUfornia; however, the more northerly material from 
Wyoming, Montana, and British Cohmibia comes closer to that 
illustrated, suggesting there may be a iiorth-soutli cline in this char- 
acter rather than the east-west variability suggested by others. In 
addition to the puncturation of the first metasomal tergum, the fe- 
males differ from fulgidus in having the precoxal spines approxi- 
mately four times as long as broad, and the scutellum with many 
longitudinal striae over the posterior three-fourths of the surface. 

Male: length 10 mm., wing lengtli 7 mm. 

Pile of face rather long and pale, concealing clypeus; pile of vertex 
and upper genal areas variable, becoming much longer^ finer, and 
pure white below; mesoscutum and scutellum with abundant, long, 
erect pubescence, weakly tinged with oclireus and occasionally 
mixed with black pile on mesoscutel and scutellar discs; pile of 
mesepisterna long, fine, and light grey; propodeum with long, dense 
fringes of pale grey pile at lateroposterior margins, extending half- 
way down to pedicle, lateral and posterior faces sparsely covered 



Revision of the Bee Genus Colletes 235 

With erect, pale grey pile; legs with pile sparse, long, and white to 
pale grey; first metasomal tergiim with apical fascia weak, rather 
narrow, and pale grey, lateral fringes of pile extending to the apical 
fascia, sometimes interrupted towards apex, discal area with abun- 
dant, long, erect, pale grey pile, not at all concealing surface; meta- 
somal terga two to five with fasciae broad and white; metasomal 
sterna with very narrow apical fasciae of short, white pubescence. 
Antennae long, deep reddish brown, flagellar segments approxi- 
mately one and one-half times as long as broad; malar spaces five- 
eighths as long as broad; clyjjcus weakly convex^ finely and densely 
punctate over the basal one-half and down a median longitudinal 
line, punctures not at all striate, the apicolateral margins shiny, 
sparsely punctate with weak striate punctures; vertex dull, densely 
punctate. Prothoracic spines short and roughly triangular; meso- 
scutum densely, coarsely punctate over anterior one half and lateral 
margins; scutellum with discal area sparsely punctate with shiny in- 
terspaces, punctures approximately one to two puncture widths 
apart, becoming much sparser towards anterior margin; wings 
dusky, nervures brown; legs deep brown to black; posterior basitarsi 
four times as long as broad. Second metasomal tergum with a dis- 
tinct basal depression; seventh ventral plates roughly quadrate, ex- 
panded or lobate towards the apical end, a long, lateral projection 
from the basal area of each plate; penis valves broadly truncate 
apically; gonostyli slightly more than four times as long as apical 
width. 

Female: length 11:5 mm., wing length 8.25 mm. 

Pile of face erect, sparse, and pale grey, concentrated princii:)ally 
about antennal bases; vertex with some dark pile intermixed; meso- 
scutum with dense fringes of light ochreus pile about anterior one 
fourth and lateral margins, discal area with abundant, black, erect 
pile; scutellum witli a peripheral fringe of light ochreus pile, discal 
area with abundant, erect, black pile; mesepisterna with pile tinged 
with ochreus above, becoming much longer and whiter below; pile 
of legs long and tinged with ochreus; first metasomal tergum with a 
very narrow, weak apical fascia, evident only laterally, lateral 
fringes rather weak, evident only on anterior lateral face, not usually 
reaching apical fascia, discal area sj>ax*sely covered with a few pale 
grey hairs; metasomal terga two to five with fasciae broad and 
white, second metasomal tergum with distinct basal fascia of white 
pubescence; metasomal sterna two to four with very weak fringes 
of light ochreus pile, not at all fasciate. 



236 The University Science Bulletin 

Antennae reddish brown, flagellar segments approximately as long 
as broad; malar spaces one fourth as long as broad; clypeus weakly 
convex J very coarsely and striately punctate to apex, interspaces 
shiny; vertex finely punctate with shiny interspaces • Pro thoracic 
spines long; mesoscutum very coarsely, densely^ almost rugo^ely 
punctate over anterior one half and lateral margins, surface dull^ 
impunctate area very small; scutellum rather densely and striately 
punctate, striae extending towards anterior margin^ dull, striate 
punctures almost reaching anterior margin; mesepisterna very 
coarsely and densely punctate, punctures contiguous above, becom- 
ing slightly sparser below, dull; propodeum witli basal area quad- 
rately pitted, lateral faces shiny and weakly sculx3tured, posterior 
face dull and roughened; wings dusky with abundant, light ochreus 
pubescence apically, nervures brown; legs deep reddish brown; 
posterior basitarsi three times as long as broad. Metasomal sterna 
shiny, finely and spaisely folliculated. 

It is difficult to separate the subspecies of simidans on tlie basis 
of the named forms. The division into tfie four subspecies which 
follows is not entirely satisfactory sinct^ simiilans was originally de- 
scribed from specimens labeled merely '^Colorado" and exhibiting 
features intermediate between two of the subspecies, I believe the 
typical material to be most characteristic of the Rocky Mountain 
subsx^ecies and therefore have recognized simttlans simtdans as the 
form occurring in the mountainous regions from Arizona and New 
Mexico north into Montana. A rather good representation of this 
subspecies from the mountains of Arizona and western New Mexico 
has the mesoscutum devoid of any dark hairs and the seventh 
ventral x:>lates more strongly lob ate than in those specimens oc- 
curring in the northern portion of the Great Divide, Sx^ecimens 
from Zion National Park in southern Utah are basically similar to 
tlie Arizona material but in northern Utah, Nevada, and western 
Colorado the dark hair of tlie mesoscutum becomes more prominent 
and the seventh ventral plates much more trapezoidal. This in- 
crease in the amount of black pile and the more traj^ezoidal shape 
of the seventh ventral i^lates progresses to the norths with the plates 
becoming widest in sx^ecimens taken from the valleys of Washington 
and British Columbia. The females taken in Arizona exhibit a 
marked difference from other populations of this species in having 
tlie prothoracic spines roughly triangular and strongly tending to- 
wards obhqueness. The first metasomal tergum of s. sinmlans is 
much more coarsely jiunctate than the others and the pile of the 
scutellum and the mesoscutum is x^redominantly ochreus to ochreus 



Revision of the Bee Genus Colletes 237 

grey. The oblique nature of the prothoracic spines is found in much 
of the material taken in Colorado, particularly in specimens from 
tlie higher altitudes between 4000 and 9000 feet, and this tendency 
is also evident in some of the southern Utah specimens. 

The obliqueness of the prothoracic spines is lost in s. nevadensis 
occurring in California, Oregon, Washington, and British Columbia, 
where the spines are long and sharp. 

The more northerly material found from the foothill regions east 
of the Continental Divide to the Atlantic seaboard I have con- 
sidered as mostly armatus Patton, with s. miamiensis or inter grades 
toward it occurring in the extreme south. Two males from El Paso, 
Texas, are intermediate between s, simulans and $\ miamiensis 
genitalically but differ from s. simulans in having much less dark 
hair on the mesoscutum and scutellum; in fact there are only a few 
darker hairs intermixed on the scutellar disc. Several specimens 
representing both sexes have been taken at Hattiesburg^ Mississippi, 
and prove to be an intermediate form between those from El Paso 
and those from Florida, 5, miamiensis MitchelL 

Were it not for the abundance of black pile on the thoracic dor- 
sum and the long, sharp prothoracic spines of the eastern armattts^ 
this subspecies would be very difficult to distinguish from the popu- 
lations of s. simulans occupying the Arizona-New Mexico plateaus. 
In the material taken from the footliill regions of Texas, Nebraska, 
and the Dakotas^ the prothoracic spines lose the oblique nature of 
s. simidans completely and become much longer and sharper. Ac- 
companying this elongation of the spines there is a progressive in- 
crease in the amount of black pile on the mesoscutum, scutelkim, 
and the vertex of the head, reaching a stage of almost completely 
black along the Atlantic seaboard, Here^ toOj the prothoracic spines 
reach their greatest length, extending laterally well out beyond the 
edges of tlie head. 

Tlius examination of tlie two sexes suggests that the entire group 
may have spread from the southwestern area and moved north, 
westj and east to occupy North America, The absence of any 
closely related species in the Palearctic region (Noskiewicz, 1936) 
tends to substantiate the southerly origin of this complex. ( Map 1. ) 

Colletes simulans simulans Cresson 

(Fig. 12) 

Colletes simulans Cresson, 1868, Proc. Boston Soc. Nat, Hist,, vol, 12, p. 168; 
Cockerell, 1898, Zool,, ser, 4, voL 2, p. 313; Viereck, 1903, Trans. Amer, 
Ent Soc.j voL 29, p. 57; Swenk, 1904, Canadian Ent., vol, 36, p. 94; Cock- 
erell, 1905, Psyche, vol. 12, p. 86; 1906^ Trans, Amer. Ent. Soc, vol 30, 
p. 291; Cresson, 1916, Mem, Amer. Ent. Soc, no, 1, p. 109; Tiniberlake, 
1943, Bull Anier. Mus. Nat. Hist., vol. 81, p. 397. 



2.S8 The University Science Bux^letin 

CoUetes armata, Cockerell (not Patton), 1897, Ann. Mag. Nat, Hist., scr. 6, 
vol. 19, p. 41; 1897, Bull, New Mexico Agrie. Exper. Sta-, no, 24, p. 21; 
1898, Zool., ser. 4, vol 2. p. 311; 1898, Bull, Denison Univ., vol. 11, p. 42; 
1898, Bull Univ. New Mexico, vol 1, p. 42; 1899, Ent. News, vol. 10, p. 4; 
1906, Trans, Amer. Ent, Soc,, vol. 32, p. 292. 

CoJletes higeloviae Cockerell, 1897, Ann, Mag, Nat. Hi.st., S€.'T. 6, vol. 19, p, 40; 
1897, Bull New Mexico Agric. Exper, Sta,, no, 24, p. 21; 1898, Bull. Denison 
Univ., vol. 11, p. 42; 1898, Bull Univ. New Mexico, vol 1, p. 42; 1899, 
Entom., vol 32, p, 153; 1901, Ann. Mag. Nat. Hist., ser. 7, vol 7, p, 125; 
Viereck, 1903, Trans. Amer, Ent. Soc, vol 29, p. 62; Cockerell, 1906, Trans. 
Amer. Ent. Soc, vol 32, p, 291; Swenk, 1908, Univ. Nebraska Studies, vol, 
8, p. 53; Timbcrlake, 1943, Bull. Amer. Mus, Nat, Hist,, vol 81, p, 397. 

CoUetes brevisvlnostis Viereck, 1903, Trans. Amer. Ent. Soc, vol. 29, p. 62; 
Cockerell, 1906, Trans. Amer. Ent, Soc, vol. 32, p. 291; Swenk, 1908, Univ. 
Nebraska Studies, vol. 8, p. 54; Cresson, 1928, Mem. Amer. Ent. Soc, no, 
-5, p. 58; Timberlake, 1943, Bull Amer. Mus. Nat. Hist., vol 81, p. 397, 

CoUetes coJoradensis Cockerell, 1933, Ann. Ent, Soc Amer,, vol. 26, p. 41; 
Timberlake, 1943, Bull Amer. Mus. Nat. Hist., vol. 81, p. 397. 

CoUetes tegiilaris Swenk, 1905, Canadian Ent., vol 37, p. 304; Cockerell, 1906, 
Trans. Amer. Ent. Soc, vol 32, p. 292; Swenk, 1908, Univ, Nebraska 
Studies, vol. 1, p. 58; Criddle et aL, 1924, Rept, Ent. Soc Ontario, p. 99; 
Timberlake, 1943, Bull. Amer, Mus. Nat. Hist,, vol 81, p. 397. 

The males of this subspecies have the pile of the mesoscutnm and 
scuteUum pale grey or tinged with light ochreus and a few dark 
hairs intermixed, these dark hairs not black. The tegulae and the 
nervures are a light hyaline brown. The first metasomal tergum is 
very densely and coarsely punctate with the punctures no more than 
one puncture width ajiart. The seventh ventral plates are roughly 
quadrate tending to weakly trapezoidal in the mountains of the 
Central States (fig. 12). The females have the prothoracic spines 
rather long and tending towards obliqueness apically, becoming 
much shorter and tending to be much more oblique in the moun- 
tains of New Mexico and Arizona, which at present is the southern 
known extremity of its range. The first metasomal tergum is very 
densely punctate, punctures no more than one puncture width apart. 

Distribution: This subspecies ranges from Montana southward 
into the moimtains of New Mexico and Arizona. It has been 
recorded from: Montana: Bozeman; Weeks ville. Wyoming: Rock 
Springs; the mountains near Sheridan. Colorado: Creede; Glen- 
wood Springs; Greeley; San Luis Valley; Wray. New Mexico: Al- 
buquerque; Las Cruces; Sacramento Mountains; Mescalero; San 
Ignacio; Willow Creek. Arizona; Flagstaff; Grand Canyon; House- 
rock Valley; Humphrey's Peak; Oak Creek Canyon; Sabino Basin; 
Santa Catalina Mountains; San Pedro River, Fairbanks • 

Flight records: Specimens have been caught during the period 
August 2 to September 23, 

Flower records: Aster^ Bigclovia Wrigfjtii, GrindeUa, Senecio. 
The holotype of simtdans from Colorado is in the Academy of 



Revision of the Bee Genus Colletes 239 

Natural Sciences of Philadelphia, that of bigeloviae from Mescalero, 
New Mexico, is in the United States National Museum, that of 
hrevis^nnosus from Beulah, New Mexico, is in the collections of the 
Academy of Natural Sciences of Philadelphia, and that of tegular is 
from Gering, Scotts Bluff County, Nebraska, is at the University of 
Nebraska. 

Colletes simtdans mtamiensis Mitchell 

Colletes simulans anruitus, Michener, 1947, Amer, Midland Nat., vol. 38, p. 445. 
Colletes simulans miamiensis Mitchell, 1951^ J. Elisha Mitchell Sci. Soc<, voL 67, 
p. 236. 

The subspecies, although found far from the Continental Divide, 
agrees more closely with s\ simulans than s. armattis, but ranks as 
subspecifically distinct on the basis of few dark hairs on the thoracic 
dorsum, weakly truncate and short pro thoracic spines, and denser 
pubescent covering of the wings. The seventh ventral plates re- 
semble those of s, simulans in their shorter laterobasal projections 
and broad basal areas. 

The suggested relationship to s. simulans is enhanced by the 
presence of intermediate forms from Hattiesburg, Mississippi, and 
El Paso, Texas, and the apparent absence of the species in the East 
South Central States. 

On the basis of these data it appears that the Florida specimen 
represents the eastern terminus of an east- west cline extending 
through Texas and the southern states. 

Tliis monotype was examined only once and unfortunately re- 
turned before an adequate description was compiled. To supple- 
ment the notes made at the time of examination^ the original de- 
scription follows. 

"Male — Length 9 mm.; length and breadth of face subequal; eyes 
convergent below; length of malar space about one-third its breadth; 
length of antennal segments about IM times their breadth, basal seg- 
ment of flagellum much shorter than the second, flagellum brownish, 
but the basal segment much darker; clypeus closely and deeply 
punctate, upper portion hidden by the dense pubescence; face 
above antennae dull, rugoso-punctate, vertex shining, finely and 
irregularly punctured; cheeks closely and finely punctate beneath 
the copious pubescence j pubescence whitish on head and thorax, 
slightly yellowish above, mesonotum and scutellum with a few in- 
conspicuouSj fuscous hairs; lateral angles of prothorax not spined; 
metapleural protuberance not carinate; legs dark, metatarsi slender; 
spurs yellowish; tegulae yellowish-ferruginous; wings lightly infus- 
cated, nervures and stigma piceous; third submarginal cell slightly 



240 The University Science Bulletin 

exceeding the second, the latter receiving first recurrent slightly 
basad of middle, third receiving second recurrent about one-third 
from tip; punctures of mesonotum deep and coarse, close over most 
of disc, but sparse in center of posterior half; scutellum shining, 
coarsely and deeply punctate, anterior margin impunctate, but punc- 
tures quite close along hind margin; pleura dull, rugoso-punctate 
anteriorly and above, with more distinct but close and coarse punc- 
tures below; lateral and posterior faces of propodeum coarsely 
reticulate J dorsal face short, with closely parallel striae; base of ab- 
domen deeply and distinctly but finely punctate, punctures well 
separated but not sparse; second and following terga becoming suc- 
cessively more minutely and closely punctate; apical margins of 
terga slightly depressed, reddish-hyaline beneath the thin, white 
fasciae^ discal pubescence on second and following terga fuscous, 
very short, suberect and inconspicuous; seventh sternum and genital 
armature essentially the same as in the other forms of simulans. 

**Holotype: Male, Miami, Fla,, Jan. 21, 1924 (J. Pearson) Am. 
Mus," 

Collet es simulans armattis Fatten 

(Fig, 14) 

Colletes inuequalis^ Cresson (not Say), 1868, Proc. Boston Soc, Nat. Hist.^ vol. 
12, p, 166; 1872, Trans. Amer. Ent. Soc, vol 4, p. 248. 

Colletes armata Patton, 1879, Proc. Boston Soc. Nat, Hist,, vol. 20, p. 143; 1879, 
Bull. U. S. GeoL Geog, Survey^ ser. 5, no, 3, p. 365; Robertson, ISQS, Trans. 
Anier. Ent. Soc, vol, 22, p. 116; Bridwell, 1899, Trans, Kansas Acad. Sci., 
vol. 16, p. 209; Pierce, 1904, Univ, Nebraska Studies, voL 4, p, 24; Morice, 
1904, Trans. Ent. Soc. London, p. 27, pi. 9, fig- 57^ 58 (Colletes sp.P); Robert- 
son, 1904, Canadian Ent., vol. 36, p. 275; 1906, Science, voL 23, p. 309; 
Lovell, 1907, Canadian Ent,, vol. 29, p, 364; Swenk, 1908, Univ. Nebraska 
Studies, vol. 8, p, 53; Graenicher, 1910, Bull, Pub, Mus. Milwaukee, vol, 1^ 
p. 228; Smith, 1910, Ann, Rept, New Jersey State Mus. for 1909, p. 694; 
Robertson, 1914, Ent, News, vol. 25, p, 69; Gibson, 1914, Rept, Ent, Soc. 
Ontario, p. 124; Gibson and Criddle, 1920^ Rept. Ent. Soc. Ontario, p, 131; 
Robertson, 1926, Ecology, vol 7, p. 387; 1926, Psyche, vol. 33, p. 116; 
Leonard, 1926, Cornell Agric. Exper. Sta. Mem., no. 101, p. 1021; Robert- 
son, 1928, Flowers and Insects, p, 10; Graenicher, 1935, Ann. Ent. Soc. 
Amer., vol. 28, p. 301; Brimley, 1938, Insects of North Carolina, p. 451; 
Proctor, 1938, Biol Surv, Mount Desert Region, pt, 6, p. 440 & pt, 8, 
p. 503; Timberlake, 1943, Bull Amer, Mus. Nat. Hist., vol, 81, p. 397 
( simuhins sbsp. ) . 

Colletes scltula Pat ton, 1879, Proc. Boston Soc. Nat. Hist,, vol, 20, p, 144; 
Robertson, 1895, Trans, Amer. Ent, Soc, voL 22, p. 116. 

Colletes spinosa Robertson, 1891, Trans. Amer. Ent. Soe., vol, 18, p* 60; 1895^ 
Trans. Amen Ent* Soc, voL 22^ p. 116. 

The Sw^enk (1908) synonymy in which he lists bigeloviae and 
brevispinosus as armatus is in error and as Timber! ake ( 1943 ) sug- 
gests they are synonyms for the better known simulans simulans. 

The males have black hair intermixed on the vertex, mesoscutum, 



Revision of the Bee Genus Colletes 241 

and sciitellum. The prothoracic spines are long and sharp, approxi- 
mately one and one-half times as long as the width across the base. 
The mesepisterna are obscurely punctate and roughened, and the 
first metasomal tergum is very finely punctate, with punctures tAVO 
to three pimctiire widths apart. In many specimens there is an 
admixture of black pile along the lower inner orbital margins. The 
seventh ventral plates are particularly quadrate and lobate apically 
(Figure 14), 

In tlie females the pile of the vertex, the mesoscutum, and the 
scutellum is predominantly black. The prothoracic spines are very 
long and sharp, protruding well beyond the sides of the head; the 
fascial foveae are deep and shiny; the tegulae are deep brown, al- 
most black; the scutelKim is more striate than punctate to the 
anterior margin; and the mesepisterna are more coarsely punctate, 

Distrihtition: This species is found in abundance throughout the 
northern Great Plains to the Atlantic seaboard, recorded southward 
to North Carolina. Marginal localities include King^s County, Nova 
Scotia; Fort Coulonge, Quebec; Aweme, Manitoba; Bilby, Alberta; 
Malcolm, Nebraska; and Raleigh, North Carolina. 

Flight records: The subspecies flies from August 2 until October 1. 

Plant records: Aster ^ Solidago, Solidago nemoralis. 

A female, Pelham, N. H,, September % 1905 (Bridwell) and a 
male, Nelson, N. H., August 1, 1907, are hereby designated neo- 
type and nc allotype of armattis. Both are in the collections of the 
United States National Museum, A female, number 9697, and a male, 
number 6876, both from Illinois ^ are hereby designated lectotype 
and lectoallotype of spinosa, and are in the Illinois Natural History 
Survey Collections, 

Colletes simulans nevadensis Swenk ■ 

(Fig. 13) 

Colletes nevadenms Swenk, 1908^ Univ. Nebraska Studies, vol, 8, p, 52, 
Colletes simulans nevadensis Tiraberlake, 1943, Bull Amer. Mus, Nat. Hist., 
vol. 81, p. 402; 1951^ Wasniann J. BioL, voL 9, p, 207. 

The male has the pile of the face^ the thorax, and the abdomen 
weakly tinged with light yellow, the pubescence, particularly the 
fasciae, is denser and the fasciae somewhat broader. The protho- 
racic spines are slightly longer than the width across the base. The 
seventh ventral plates are trapezoidal in shape, much more so than 
the quadrate form from the southwestern mountains (Fig. 13). 
The malar spaces are slightly reduced, being scarcely half as long 
as wide. 



242 The University Science Bulletin 

The female has the pile of the body weakly tinged with yellow. 
The malar spaces are slightly reduced. The prothoracic spines 
are long and sharp, protruding to the edge of the head* The first 
metasomal tergum has the punctures finer and slightly sparser, 
ranging from two to three puncture widths apart. 

Distribution: The subspecies is found in the lowland areas of 
Utah, Nevada, California, Washington, Oregon, and British Colum- 
bia, It undoubtedly occurs in the valleys of Idaho and possibly 
western Colorado but has not yet been taken there. Peripheral 
localities include: Penticton and Oliver in British Columbia, River- 
side and Los Angeles Counties, in California, and Salt Lake City 
and Emery County in Utah. * 

Flight records: Flight records are from August 7 until November 
26. A great number of specimens determined as nevadensis taken 
particularly from the mountains of California have proved to be 
fulgidiis Swenk. I believe simuhns nevadensis to occur only in 
the lowland areas^ being replaced by ftdgidtis in the mountains. 

Plant records: Baccharis emoryi, Chrijsothamnus, Ericameria 
ericoides^ Eriogoniim^ Gutierrezia californica, Apia pappus { I so coma ) 
veneta var, vernonioides, Lepidosjmrtum^ MeUlotus alba. 

The holotype from Reno, Nevada, is in the collections of the 
University of Nebraska. 

CoUetes angelicus Cockerell 

(Fig. 15) 

CoUetes angelicus Cocterell, 1905, Bull. So, California Acad. Sci,, vol 4, p. 32; 
Griddle et al, 1924, Kept. Ent. Soc. Ontario, p, 99 (doubtful record); 
Timberlake, 1943, Bull Amer. Mus. Nat. Hist., vol 81, p. 402. 

Both sexes of this species can readily be distinguished by having 
the prothoracic spines obliquely triuicate and by having their pos- 
terior margins protruding to or beyond the anterior. It most closely 
resembles fidgidus Swenk. Griddle et ah reported angelicus from 
British Columbia in 1924. I doubt the validity of this determination 
although to my knov^ledge I do not have their specimen before me. 
The species seems to be restricted to southern California where it 
appears to replace fulgidus. The mde genitalia closely resemble 
those of fulgidus except for minor differences in the hair pattern. 
Some variation exists in the presence of black pile on the meso- 
scutum and scutelliim. In all specimens having a deep ochreus pile 
on the thoracic dorsum dark hairs are evident; however in those 
having the pile grey, dark hairs are not discernible. This would 
seem to indicate that the dark pile is deep ochreus rather than black. 



Revision of the Bee Genus Colletes 243 

In the majority of tlie males the sternal fasciae are continuous, how- 
ever in a few the fasciae are interrupted medially. The female can 
be readily separated from other members of the simidam group on 
the basis of the prothoracie spine peculiarity and the very long 
procoxal spines. 

Male: length 11 mm., wing length 7.5 mm. 

Pile of face dense and long, tinged with yellow, completely con- 
cealing clypeus and extending just slightly above antennal bases; 
pile of vertex and upper genal areas pale grey, pile becoming much 
longer and whiter below; mesoscutum witli abundant, long, erect 
pile slightly tinged with ochreus, a few darker hairs on discal area 
of the mesoscutum; scutellum with pile principally pale grey to light 
to tinged with yellow, having a few dark, almost black, hairs inter- 
mixed; mesepisterna with pile long, fine, and pale grey; propodeum 
with dense lateroposterior fringes of pale grey pile, lateral and 
posterior faces with abundant, erect, pale grey pile; legs with pile 
sparse, short and light; first metasomal tergum with fascia weakly 
tinged with yellow and complete with rather long hairs, lateral 
fringes pale grey, extending to the fascia, disc with abundant, erect, 
pale grey pile; metasomal terga two to five with fasciae much 
broader than first and much more white, fasciae very dense; terga 
three to six with discs having abundant, erect, light pile, not black; 
metasomal sterna with fasciae uniform and complete with a dense 
apical fringe. 

Antennae deep brown to black, flagellar segments approximately 
one and one-half times as long as broad; malar spaces three-fourths 
as long as broad; clypeus weakly convex, rather finely and densely 
punctate over apical one half and down median portion, lateral 
apical aspects sparsely, striately punctate with shiny interspaces; 
the vertex finely and densely punctate, dull Prothoracie spines 
obliquely truncate with posterior margin descending beyond an- 
terior; mesoscutum densely punctate, impunctate area very small; 
scutellum densely, coaisely, almost rugosely punctate over posterior 
one-third, punctures becoming sparser with shiny inters]3aces over 
median portion, anterior face shiny, impunctate; mesepisterna 
densely punctate, punctures no more than one-half puncture width 
apart; propodeum widi basal area deeply, quadrately pitted, lateral 
and posterior faces dull and roughened; tegnlae brown; wings with 
very sparse, light ochreus pubescence tending to be almost w^hiMsh 
hyaline basally, nervures brown; legs reddish brown to black; pos- 
terior basitarsi four and one-half times as long as broad. First 
metasomal tergum densely punctate with x^unctures one to two 



244 The Uni\'ersity Science Bulletin 

puncture widths apart; second metasomal tergum with punctures 
finer and denser^ no more than one puncture width apart, tergum 
having an abrupt basal depression; metasomal terga one to four 
with fasciae lying in broad, depressed apical margins, these de- 
pressed margins hght brownish hyahne; sterna shiny, rather weakly 
and sparsely foUicuIated; the seventh ventral plates resemble ful- 
gidus but much narrower and more elongate (fig, 15), 

Female: length 11 mm,, wing length 8 mm. 

Pile of face erect and pale grey, clumped principally about 
antennal bases; vertex with pile tinged with ochreus, pile becoming 
longer and pale grey below; mesoscutum with pile pale grey to light 
ochreus intermixed with abundant black pile on discal area; scu- 
tellum witli an admixture of light ochreus and black pile about 
peripheral margins; mesepisterna with pile long, fine, and pale grey; 
propodeum with dense fringes of pile along lateroposterior margins 
extending down towards pedicel, lateral and posterior faces with 
abundant, erect, pale grey pile; j)ile of legs light ochreus, long, and 
dense; first metasomal tergum with apical fasciae weak and narrow, 
easily removed, lateral fringes of light ochreus pile extending to 
fascia, discal area with scattered^ pale grey pile, particularly on 
anterior face; metasomal terga two to five with fasciae broad and 
rather dense, second metasomal tergum with a broad basal fascia; 
terga three to six with the discs having scattered, ochreus to deep 
testaceous, erect pile, not at all concealing surface; metasomal sterna 
two to five with weak lateral clumps of pile, not continuous through 
middle. 

Antennae reddish brown, flagellar segments seven-eighths as long 
as broad; malar spaces three-eighths as long as broad; clypeus 
weakly convex, densely, striately punctate to the apex; fascial foveae 
greatly broadened above and deep, extending over half way to 
lateral ocelli; vertex shiny with many fine punctures. Pr other acic 
spines obliquely truncate with posterior margin descending beyond 
anterior; mesoscutum very coarsely almost contiguously punctate 
on median area, impunctate area very small; scutellum very coarsely 
and densely punctate over posterior one half, anterior half with 
punctures sparse and almost absent, a deep median longitudinal 
sulcus extending almost to anterior margin; mesepisterna dull and 
very coarsely and contiguously punctate; tegulae deep brown; wings 
dusky with sparse, ochreus pubescence, nervures brown; legs deep 
reddish brown to black; posterior basitarsi four times as long as 
broad. First metasomal tergum rather densely punctate with fine 
punctures, punctures approximately one to two puncture widths 



Revision of the Bee Genus Colletes 245 

apart; second tergum with punctures very fine, folliclelike, and 
dense, apical fasciae in weakly depressed margins, fascial depres- 
sions hyaline; metasomal sterna sparsely folliculated with rather 
coarse follicles, 

Distribution: California: Antiocli; Contra Costa County; Berkeley; 
Riverside; Analieim, Orange County; Morro Bay; Los Angeles. 

Flight records: The species has been caught in abundance be- 
tween August 21 and October 25 in southern and central California. 
However, I have two specimens from Berkeley, California, which 
were collected on April 20, 1937, This would indicate that the 
species has two generations or probably one and a partial spring 
generation. 

Plant records: Eriogonum^ Hcmizonia paniculata^ Isocoma ver- 
nonioides. 

The holotype from California is in the collections of the Citrus 
Experiment Station, Riverside, Cahfornia, 

Colletes fulgidus fidgidus Swenk 

(Fig. 16) 

Colietes fulgidus Swenk, 1904, In Viereck, Canadian Ent, vol, 36, p. 95; 1908, 
Univ. Nebraska Studies^ vol. 8, p, 50; Gibson and Griddle, 1920^ Rept. Ent. 
Soc, Ontario, p. 131; Timberlake, 1943, BuIL Amer. Mus. Nat, Hist,, vol. 
81, p. 396, 

This species ranges from California and Nevada across the south- 
ern Great Basin to the Rocky Mountains, Swenk recorded the 
species from Nebraska and Texas as well as other northern and far 
western states. I have not seen any specimens from either Nebraska 
or Texas otlier than a few females determined as ftdgidus by him. 
These specimens are louisae Cockerell and simulans simulans. No 
males have as yet been taken from Nebraska, New Mexico, or 
Texas, where it is probably replaced by the more southerly louisae. 
The males of the species are difficult to distinguish without genitahc 
examination and even then a series of characters is necessary for 
accurate determination. This sex often shows considerable varia- 
tion from the typical series, having the color of the thoracic pile 
varying from pale grey to light ochreus. The tlioracic spines are 
rather blunt in some but rather long and sharp in others* A very 
few specimens lack dark pile on the mesoscutum and the scutellumj 
and in some tliere is a weak rudiment of a basal fascia on the sec- 
ond metasomal tergum. The females are difficult to segregate with 
certainty from lotdsae and some specimens show the first metasomal 
tergum rather coarsely punctate, bearing a close superficial resem- 
blance to the simulans complex. While the typical material from 



246 The University Science Bulletin 

the Big Horn Mountains of Wyoming has an almost impuiictate or 
weakly folHculated first tergum, other specimens from the western 
part of America show rather coarse but sparse puncturation. The 
second metasomal tergiim, mihke that of louisae^ is finely and 
densely foUicultited. Similarly, the apical sterna of fulgidus are 
uniformly, finely folHculated^ while the sterna of louisae have 
sparse^ fine punctures restricted to the lateral and the extreme 
posterior surfaces, 

Male: length 9 mm., wing length 6.5 mm. 

Pile of face long, white^ concealing clypeus and antennal basal 
area; vertex with pile light tinged with pale grey; upper genal areas 
with pile long and pale grey^ becoming longer and more white be- 
low; mesoscutum with pile tinged with grey, long, erect, and fine; 
scutellum with pile pale grey to tinged with ochreus, a few darker 
hairs intermixed; mesepisterna with pile long^ fine^ and white; 
propodeum with weak fringes of long, pale grey pile on latero- 
posterior margins, lateral and posterior faces with a sparse covering 
of long, erect, pale grey pile; pile of legs very sparse, fine^ and 
whitish; first metasomal tergum with apical fasciae narrow, com- 
posed of long, raggedy pale grey pubescence, lateral fringes of pale 
grey pile weak extending to apical fascia, discal area with abundant, 
erect, long, pale grey pile; metasomal terga two to five with fasciae 
composed of weak, ragged, white pubescence, discal areas of terga 
three to six with abundant, short, ochreus to grey pile, not at all 
concealing surface; metasomal sterna with apical fringes of short, 
white pile, slightly longer at extreme lateral margins. 

Antennae reddish brown, flagellar segments one and one-fourth 
times as long as broad; malar spaces three fourths as long as broad; 
clypeus convex, finely and densely punctate over basal one half and 
down a flattened, median longitudinal line, not rugosely punctate, 
apicolateral faces shiny, impuiictate; vertex distinctly punctate with 
shiny interspaces, Prothoracic spines long and sharp, about one 
and one-half times as long as width across base; mesoscutum rather 
finely punctate, punctures approximately one puncture width apart 
on anterior and lateral faces, beconuiig sparser in median discal 
area; scutellum coarsely punctate, punctures approximately one 
puncture width apart medially, becoming much sparser toward 
anterior face; mesepisterna rather finely punctate, punctures ap- 
proximately one puncture width apart above to one and a half 
puncture widths below, interspaces shiny; propodeum with basal 
area deeply pitted ^ lateral and posterior faces dull and roughened; 
tegulae dark brown hyaline; wings dusky, nervures brown; legs 



Revision of the Bee Genus Colletes 247 

deep reddish brown; posterior basitarsi four and a half times as 
long as broad. First metasomal tergum deeply punctate with punc- 
tures one to two puncture widths apart, interspaces shiny; second 
metasomal tergum with punctures finer and closer, especially on 
anterior margin, tergum distinctly depressed basally; metasomal 
sterna shiny and sparsely foUiculated on lateroposterior one half 
of each sternum; seventh ventral plates as illustrated ( fig- 16 ) . 

Female: length 10,5 mm,, wing length 7 mm. 

Pile of face long, white and dense about antennal bases and 
middle inner orbital margins, a few long hairs overhanging clypeus; 
vertex with a few, light ochreus hairs, particularly in and about the 
ocellar triangle; upper genal areas with pile tinged with grey, 
becoming very fine and much longer below; mesoscutum with pile 
light ochreus about anterior and hiteral margins, discal area with 
pile black; scutellum with a peripheral rim of pile tinged with 
ochreus, disc with abundant black pile; mesej)i sterna with pile long, 
fine and pale grey; legs with pile short, rather dense on posterior 
legs, and tinged with ochreus; first metasomal tergum with apical 
fascia weak, interrupted medially and evident only as a fascia at 
lateral one third, lateral fringes of pile dense, extending to apical 
fascia, discal area sparsely covered with erect, fine, pale grey pile; 
metasomal terga two to five with fasciae very broad, dense, and 
pure white, second metasomal tergum with a basal fascia inter- 
rupted medially; metasomal sterna with a few erect, palG grey hairs, 
not forming a fascia. 

Antennae reddish brown, flagellar segments about as long as 
wide; malar spaces one- third as long as broad; clypeus flattened 
medially, coarsely, striately punctate to the apex, ridges and inter- 
spaces shiny; vertex shiny with a few scattered punctures. Pro- 
thoracic spines long, about twice as long as width across base, 
extending laterally to sides of the head; mesoscutum very densely 
and coarsely punctate over anterior one-half and lateral margins, 
impunctate area large; scutellum densely pvmctate about lateral 
and posterior faces, discal area sparsely and finely punctate with 
punctures anywhere from one to three puncture widths apart, an- 
terior one-third shiny, impunctate; mesepisterna very densely, almost 
contiguously punctate; propodeum with deep, broad, quadrate pits, 
propodeum witli lateral and posterior faces weakly rugose and 
shiny; tegulae deep brownish hyaline; wings dusky, nervures brown; 
legs deep brown; posterior basitarsi three and one-half times as 
long as broad. First metasomal tergum shiny, very weakly and 
sparsely punctate, punctures most dense laterally where they are 



248 The University Science Bulletin 

three to four puncture widths apart; second tergum shiny and 
sparsely folliculated; metasomal sterna densely folliculated over 
posterior one half of each sternum. 

Distrihution; The species is found in abundance in the higher 
regions of Cahfornia, Oregon, Washington, Idaho, Montana, Wyo- 
ming, northern Utah, and Colorado, circumscribing the Great Basin 
region. Marginal locahties are; Tonopah, Nevada; Bear Valley, 
San Bernardino County, California; Salmon Arm, British Columbia; 
Lethbridge, Alberta; Craters of the Moon, Idaho; Missoula, Mon- 
tana; Custer, South Dakota; Aspen, Colorado; and Vernal, Utah. 

Flight records: The species flies from May 7 until October 16, 
occurring in abundance during all the summer months. 

Plant records: Chaenactis stcrioidcs^ Clarkia^ Encelia^ Eriogomim, 
Grindelia, Isocoma vernonioides, Medicago sativa, Melilotus alba, 
Salix, Solidngo. 

The holotype from the Big Horn Mountains, Wyoming, is in the 
collections of the University of Nebraska. 

Collet es fulgidus longiphimosus sp. nov. 

This subspecies formerly was included w^ith fulgidus ftdgidtts; 
however it is readily distinguished in both sexes by the extremely 
long and dense pile of the head, tliorax, and abdomen. The sub- 
species appears to be a coastal race of tlie generally montane /* 
fulgidus and has been collected from various localities along the 
Californian coast. The male differs from /. fulgidus in having the 
malar spaces as long as wide, the prothoracic spines vestigial, al- 
most absent, the puncturation of the first metasomal tergum finer 
and sparser and the pile of the body very long, dense, and plumose. 
The black pile is evident on the scutellum and the mesoscutum. In 
the females of this subspecies the malar spaces are approximately 
one-half as long as broad; the protlioracic spines are roughly tri- 
angular and obtuse; and the pile, principally of the head and thorax 
is exceedingly long and plumose. 

Distribution: The extreme western coastal region of California 
from Humboldt County to San Luis Obispo County, inland as far 
as Sacramento. 

Holotype male, allotype female and 9 paratypes: Montara, San 
Mateo County, California, June 10, 1939 (C, D, Michener); para- 
types; 27 males, Dillon Beach, Marin County, California, May 22, 
1949 (W, W. Middlekauff); 1 male, San Francisco, California, May 
21, 1911 (J. A. Kusche); 2 females, Sacramento, California, June 26,